Supply circuit for a heat exchange medium for a consumer, industrial plant and method for operating them

Abstract

A supply circuit for a heat exchange medium for a consumer having an inflow line for the heat exchange medium and a return line for the heat exchange medium, the lines being connected to one another by way of a consumer heat exchanger. A pumping device for conveying the heat exchange medium through the supply circuit is a frequency-controlled pumping device having a conveying pump and a frequency converter which is assigned to the conveying pump. For an industrial plant, a primary circuit is connected to a supply circuit of this type as a secondary circuit. In either case, the supply circuit is operated selectively in one of two operating modes. In a first operating mode, the temperature of the heat exchange medium which enters into the consumer heat exchanger from the inflow line is set by way of an admixture control operation in which the temperature of the heat exchange medium which enters into the consumer heat exchanger from the inflow line is set by way of an actuation of the valve. In a second operating mode, the temperature of the heat exchange medium which enters into the consumer heat exchanger from the inflow line is set by a volumetric flow control operation, by the frequency converter of the pumping device being actuated.

What is claimed is: 
     
         1 . A supply circuit for a heat exchange medium for a consumer comprising:
 a) an inflow line for a heat exchange medium and a return line for the heat exchange medium, the lines being connected to one another by way of a consumer heat exchanger;   b) a pumping device for conveying the heat exchange medium through the supply circuit, wherein   c) the pumping device is a frequency-controlled pumping device with a conveying pump and a frequency converter which is assigned to the conveying pump.   
     
     
         2 . The supply circuit according to  claim 1 , whrein the inflow line and the return line are connected to one another by way of a circulation line in such a way that heat exchange medium can be guided out of the return line in the supply circuit into the inflow line. 
     
     
         3 . The supply circuit according to  claim 2 , wherein there is a valve, by means of which the proportion of the heat exchange medium which flows through the circulation line into the inflow line can be set. 
     
     
         4 . The supply circuit according to  claim 3 , wherein the valve is arranged in the circulation line. 
     
     
         5 . The supply circuit according to  claim 2 , wherein the circulation line opens into the inflow line upstream of the conveying pump. 
     
     
         6 . The supply circuit according to  claim 3 , wherein the frequency-controlled pumping device and/or the valve can be actuated by means of a control device. 
     
     
         7 . The supply circuit according to  claim 6 , wherein the control device is connected to a sensor system, by means of which an inlet pressure of the heat exchange medium on an inlet side of the conveying pump and/or an outlet pressure of the heat exchange medium on an outlet side of the conveying pump and/or a temperature of the heat exchange medium in the inflow line on an inlet side of the consumer heat exchanger and/or the temperature of the heat exchange medium in the return line on an outlet side of the consumer heat exchanger can be detected, and associated sensor responses can be transmitted to the control device. 
     
     
         8 . The supply circuit according to  claim 6 , wherein the control device is connected to a consumer sensor system, by means of which at least one operating parameter of a consumer can be detected and can be transmitted to the control device. 
     
     
         9 . An industrial plant comprising a primary circuit for a heat exchange medium, the primary circuit being connected to at least one secondary circuit for the heat exchange medium for a consumer, an inflow line of the secondary circuit being connected to an inflow line of the primary circuit, and a return line of the secondary circuit being connected to a return line of the primary circuit, wherein the secondary circuit is a supply circuit according to  claim 1 . 
     
     
         10 . A method for operating a supply circuit comprising:
 a) selecting one of two operating modes to operate a supply circuit, the supply circuit comprising the supply circuit of  claim 3 , wherein
 aa) in a first operating mode, a temperature of the heat exchange medium which enters into the consumer heat exchanger from the inflow line is set by way of an admixture control operation, in the case of which the temperature of the heat exchange medium which enters into the consumer heat exchanger from the inflow line is set by way of an actuation of the valve; 
 ab) in a second operating mode, the temperature of the heat exchange medium which enters into the consumer heat exchanger from the inflow line is set by way of a volumetric flow control operation by the frequency converter of the pumping device. 
   
     
     
         11 . The method according to  claim 10 , wherein in a third operating mode, the temperature of the heat exchange medium which enters into the consumer heat exchanger from the inflow line is set by way of a combination control operation, in the case of which the admixture control operation and the volumetric flow control operation are combined with one another.