Method for improved energy recovery in inlet-air and waste-air heat exchangers of combined circulation systems for air-conditioning and ventilation systems

Abstract

Method for controlling the operation of inlet-air and waste-air heat exchangers of combined circulation systems for combined circulation systems, comprising:supplying at least one inlet-air stream and/or at least one waste-air stream of an air-conditioning and ventilation system to one or more heat exchangers through which a medium flows:measuring a temperature difference, ΔT value, between a flow and a return temperature of the medium for each heat exchanger;setting the media flow through the relevant heat exchanger in such a manner that the ΔT value for the relevant heat exchanger is regulated to a target value.

1 . Method for controlling the operation of inlet-air and waste-air heat exchangers of combined circulation systems for combined circulation systems, comprising:
 supplying at least one inlet-air stream and/or at least one waste-air stream of an air-conditioning and ventilation system to one or more heat exchangers through which a medium flows:   measuring a temperature difference, ΔT value, between a flow and a return temperature of the medium for each heat exchanger;   setting the media flow through the relevant heat exchanger in such a manner that the ΔT value for the relevant heat exchanger is regulated to a target value.   
     
     
         2 . Method according to  claim 1 , wherein the setting of the media flow through the heat exchanger is accomplished in such a manner that a rotational speed or the rotational speeds of at least one speed-regulated pump is/are adapted. 
     
     
         3 . Method according to  claim 1 , wherein the setting of the media flow through the heat exchanger is accomplished in such a manner that a degree of opening of a delta-T control valve is regulated for each of the heat exchangers. 
     
     
         4 . Method according to  claim 1 , further comprising:
 determining and regulating the delta-T control valve which has the furthest degree of valve opening in the inlet-air and waste-air line respectively,   adapting the pressure increase due to one or more speed-regulated pumps such that the power consumption of the system is reduced to the minimum necessary.   
     
     
         5 . Method according to  claim 1 , further comprising:
 in the case of a ΔT value of a heat exchanger which is too low compared with the target value, reducing the degree of opening of the relevant delta-T control valve to reduce the flow rate of the medium through the heat exchanger and   in the case of a ΔT value of the heat exchanger which is too high compared with the target value, increasing the degree of opening of the relevant delta-T control valve to reduce the flow rate of the medium through the heat exchanger.   
     
     
         6 . Method according to  claim 1 , further comprising:
 automatic determination of an operating state of the air-conditioning and ventilation system based on the measured ΔT values, wherein the operating state comprises a heating or cooling operating state,   transferring target values for the determined operating state to the respective delta-T control valves of the heat exchanger in the inlet-air and in the waste-air stream,   implementing the regulation of the degree of opening for each delta-T control valve using the transferred target value.   
     
     
         7 . Method according to  claim 6 , wherein the automatic determination of the operating state of the air-conditioning and ventilation system comprises:
 determining for each heat exchanger with reference to the ΔT values whether this is in a neutral operating state, in a heating operating state or in a cooling operating state; and   determining in which operating state the majority of the heat exchangers are located, wherein heat exchangers located in a neutral operating state are not taken into account and wherein the operating state of the air-conditioning and ventilation system is set as the operating state of the majority of the heat exchangers,   if the same number of heat exchanges should be located in the heating and in the cooling operating state, the operating state corresponding to the heat exchanger with the ΔT value having the largest amount is set.   
     
     
         8 . Method according to  claim 1 , further comprising:
 supplying heat or cold for temperature control of the inlet air to the one or more of the heat exchangers in the inlet-air stream.   
     
     
         9 . Method according to  claim 8 , further comprising:
 adapting the target value for the ΔT value of the one or more of the heat exchangers in the inlet-air stream into which heated or cooled medium is supplied to prevent the supplied energy being supplied to the waste-air heat exchangers via the return.   
     
     
         10 . Method according to  claim 1 , further comprising:
 determining whether a ΔT value of a heat exchanger is less than a fixed minimum value over a defined time interval and   if this is the case, completely closing the delta-T control valve of the heat exchanger.   
     
     
         11 . Method according to  claim 10 , comprising:
 opening the closed delta-T control valve of the heat exchanger after a pre-determined time interval;   repeating the determination of whether the ΔT value of a heat exchanger is less than a fixed minimum value over a defined time interval and if this is the case, repeated complete closure of the delta-T control valve of the heat exchanger.   
     
     
         12 . Method according to  claim 1 , wherein:
 a plurality of heat exchangers are each arranged in an inlet air stream,   the inlet air is cooled by a first dehumidifying heat exchanger in order to reduce the moisture content of the inlet air and   the inlet air is again supplied with thermal energy by means of a downstream heat exchanger,   wherein the two heat exchangers are connected via a common media circuit and wherein the media flow through the dehumidifying heat exchanger and the downstream heat exchanger is regulated in such a manner that a ΔT value between a flow and a return temperature of the medium for each of these heat exchangers is regulated to an EKR target value.   
     
     
         13 . Device for regulating the operation of inlet-air and waste-air heat exchangers of combined circulation systems for air-conditioning and ventilation systems comprising:
 sensors for measuring a temperature difference, ΔT value, between a flow and return temperature of the medium for each of the inlet-air and waste-air heat exchangers;   a controller for setting the media flow through the relevant heat exchangers in such a manner than the ΔT value for the relevant heat exchanger is regulated to a target value, wherein the setting of the media flow comprises a rotational speed regulation of at least one pump and/or regulating a degree of opening of a delta-T control valve for each of the heat exchangers.   
     
     
         14 . Combined circulation system station for an air-conditioning and ventilation system comprising:
 one or more heat exchangers in at least one inlet-air stream of the air-conditioning or ventilation system and one or more heat exchangers in at least one waste-air stream of the air-conditioning and ventilation system, wherein a medium flows through the inlet-air heat exchanger and the waste-air heat exchanger;   sensors for measuring a temperature difference ΔT value between a flow and return temperature of the medium for each of the heat exchangers;   a controller for setting the media flow through the relevant heat exchanger in such a manner that the ΔT value for the relevant heat exchanger is regulated to a target value, wherein the setting of the media flow comprises a rotational speed regulation of at least one pump and/or regulating a degree of opening of a delta-T control valve for each of the heat exchangers.   
     
     
         15 . Machine-readable storage medium which contains instructions which, when executed in a processor of a controller of a combined circulation system for air-conditioning and ventilation systems, are suitable for executing the method according to  claim 1 .