Method for regulating the room temperature in a room or in a group comprising multiple rooms, and apparatus for carrying out the method

Abstract

The present disclosure provides methods and systems for regulating the room temperature in a room or in a plurality of rooms, the room temperature can be regulated by regulating the mass flow of a heat-carrying fluid flowing through a heat exchanger according to a determined current room temperature. In accordance with some embodiments, a temperature sensor in the room can be dispensed that can determine the current room temperature, in each case the mass flow of the heat carrying fluid through the heat exchanger and the flow temperature prevailing at the input to the heat exchanger and the return temperature prevailing at the output of the heat exchanger are measured, and that a temperature assigned to the determined values of the mass flow, the flow temperature and the return temperature is output as the current room temperature and used for regulation.

Claims

1. A method for regulating room temperature in a room or in a group comprising a plurality of rooms, the method comprising: regulating a mass flow of a heat-carrying fluid flowing through a heat exchanger or consumer according to a determined current room temperature (t.sub.i,j); determining the current room temperature (t.sub.i,j), in each case by, measuring the mass flow of the heat carrying fluid through the heat exchanger and a flow temperature of the fluid prevailing at the input to the heat exchanger and a return temperature of the fluid prevailing at the output of the heat exchanger; and outputting a temperature assigned to the determined values of the mass flow, a flow temperature and the return temperature as the current room temperature and used for said regulation.

2. The method of claim 1, wherein the current room temperature (t.sub.i,j) is output in accordance with a function t.sub.i,j=F(t.sub.V,j,t.sub.R,jm.sub.j)+t.sub.corr(T) in which t.sub.V,j and t.sub.R,j designate the flow and return temperature respectively and m.sub.j the mass flow at time T.sub.j, and t.sub.corr(T) is a time-dependent correction term which takes into account the thermal storage capacity of the respective heat exchanger or consumer.

3. The method of claim 2, wherein the current room temperature (t.sub.i,j) is output in accordance with the function t.sub.i,j=0.5.Math.(t.sub.V,j+t.sub.R,j)(m.sub.j/m.sub.0).Math.((t.sub.V,jt.sub.R,j)/(t.sub.V,0t.sub.r,0)).Math.(t.sub.V,0+t.sub.R,02t.sub.i,0)+t.sub.corr(T) in which t.sub.i,0 designates a design room temperature, t.sub.V,0 a design flow temperature, t.sub.R,0 a design return temperature and m.sub.0 a design mass flow.

4. The method of claim 1, wherein in regulating the room temperature, the flow temperature is identical for all heat exchangers or consumers of a group.

5. The method of claim 1, wherein the mass flow of the heat-carrying fluid through the heat exchanger is changed by means of an associated control valve.

6. The method of claim 1, wherein the heat exchanger is part of a surface heater/cooler.

7. An apparatus comprising: a heat exchanger actively connected to a room to be regulated by an input to a flow line and by an output to a return line, a control valve which controls a mass flow through the heat exchanger, a flow temperature sensor which records a flow temperature in the flow line, a return temperature sensor which records a return temperature in the return line, a flow sensor which records the mass flow through the heat exchanger, and a control unit comprising, at least three inputs connected to the flow temperature sensor, the return temperature sensor and the flow sensor, an output actively connected to the control valve, an assignment part configured to assign a room temperature to the values applied to the inputs for the mass flow, the flow temperature and the return temperature, a regulator part configured to actuate the control valve according to a deviation of the assigned room temperature from a prespecified setpoint; and wherein the control unit is configured to: regulate a mass flow of a heat-carrying fluid flowing through the heat exchanger according to a determined room temperature; determine the room temperature, in each case by, measuring the mass flow of the heat carrying fluid through the heat exchanger and a flow temperature of the fluid at the input to the heat exchanger and a return temperature of the fluid at the output of the heat exchanger; and outputting the assigned temperature to the determined values of the mass flow, the flow temperature and the return temperature as the current room temperature and used for regulation.

8. The apparatus of claim 7, wherein the flow sensor and the control valve are arranged in the return line.

9. The apparatus of claim 7, wherein the heat exchanger is part of a surface heating/cooling system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in more detail below with reference to exemplary embodiments in conjunction with the drawings.

(2) FIG. 1 shows the hydraulic and control schematic of a conventional heating/cooling system based on surface heaters/coolers;

(3) FIG. 2 shows the schematic diagram of an individual regulation of a room with surface heating/cooling according to an exemplary embodiment of the invention; and

(4) FIG. 3 shows the thermal situation in the region of a floor heater which is based on the invention.

DETAILED DESCRIPTION

(5) The method and the apparatuses for one or a group of surface heating or cooling systems (hereinafter referred to as consumers) in particular relates to a method for individual room temperature regulation with motorized control valves for regulating the flow or energy respectively through the consumer in order to maintain the room temperature constant for changes in load, e.g. a change in the internal load due to people (disturbance step), or in order to adjust the room temperature in the case of user intervention (setpoint change).

(6) The method is distinguished in that the regulation is based on the measurement and evaluation of the energy supplied and dissipated (flow through the consumer, flow and return temperature of the consumer) by means of program code taking into account the thermodynamic relationships, and therefore a direct measurement of the room temperature is not necessary.

(7) The individual room temperature regulating apparatus 24 shown in FIG. 2 for the individual room temperature regulation of a single room Ri uniquely assigned to a consumer comprises the devices listed below: a flow temperature sensor 29 for measuring the flow temperature (tV) of a consumer or of a group of consumers which is (are) arranged in a flow line 25; A return temperature sensor 30 for measuring the return temperature (tR) of a consumer which is uniquely assigned to a room Ri, in this case a surface heater/cooler 27; a flow sensor 28 for measuring mass flow (m) of the consumer or of a group of consumers; in the case of a group of consumers, the regulator includes a program code for distributing the measured total mass flow (automatic dynamic balancing, such as is the subject matter of the Swiss patent application No. 01102/11 submitted on 30 Jun. 2011) between the individual consumers which in each case are uniquely assigned to a room Ri; a control valve Vi with continuous actuation for limiting and regulating the mass flow (m) through a consumer which is uniquely assigned to a room Ri, in this case the surface heater/cooler 27; (optionally) a control device (setpoint device 32) for shifting the setpoint (adjusting to suit a temporary indisposition), optionally with an integral room temperature measurement for one or a group of rooms; the adjustment to suit a temporary indisposition (setpoint shift) can also be carried out by means of a software interface/web view; and a control unit 31 (in the form of a program code) for individual room temperature regulation taking into account the thermal behavior of a room Ri which is uniquely assigned to a consumer (27), which control unit comprises an assignment part 31a and a regulator part 31b.

(8) The associated thermal situation in the region of the surface heater/cooler 27 is reproduced schematically in FIG. 3. In quasi-steady-state operation, the heat flow Qh(T), which is dissipated or absorbed by room Ri and is a function of the room temperature tRa and of the floor temperature tFb, corresponds to the heat flow QF(T), which is dissipated or absorbed by fluid flowing through the underfloor heater 27 to the consumer. In this state, the system is in thermal equilibrium, in which there is a clear relationship between fluid temperature tF (mean temperature between flow temperature tV and return temperature tR of the consumer) and the room temperature tRa as a function of the heat flow conducted through the consumer. This relationship is shown schematically in FIG. 3 and applies equally to non-steady-state situations taking into account the thermodynamic relationships.

(9) The program code for regulating the room temperature (control unit 31) takes into account the thermodynamic behavior of the system by means of the configuration or by means of a method integrated within the program code for automatically adjusting the regulation parameters for automatic configuration to suit the system. A relationship between the time-dependent change in the room temperature tRA(T) and the time-dependent behavior of the fluid temperature tF(T) and the heat QF(T) dissipated or absorbed by the fluid in the event of disturbance steps and setpoint changes is therefore stored in the program code for the regulation and is used to regulate the individual room temperature.

(10) As the heat cannot be dissipated directly but has to be conducted through the consumer, the associated storage mass which, in the example of FIG. 3, comprises at least the base layer 33 and the top layer 34, leads to a time delay in the case of non-steady-state operation of the system. With this type of regulation, the flow temperature tV remains unaffected, so that the regulation can be described as return temperature regulation.

(11) An instantaneous room temperature ti,j in the room Ri is assigned in the assignment part 31a of the control unit 31 to the measured values of the flow temperature (tV,j), the return temperature (tR,j) and the mass flow (mj) determined at a particular time Tj in accordance with the following equation (1):
t.sub.i,j=0.5.Math.(t.sub.V,j+t.sub.R,j)(m.sub.j/m.sub.0).Math.((t.sub.V,jt.sub.R,j)/(t.sub.V,0t.sub.r,0)).Math.(t.sub.V,0+t.sub.R,02t.sub.i,0)+t.sub.corr(T)(1)

(12) With the parameters:

(13) t.sub.i,j Current room temperature [ C.]

(14) t.sub.i,0 Design room temperature [ C.]

(15) t.sub.V,j Current flow temperature (group) [ C.]

(16) t.sub.R,j Current return temperature (leg) [ C.]

(17) t.sub.V,0 Design flow temperature [ C.]

(18) t.sub.R,0 Design return temperature [ C.]

(19) m.sub.j Current mass flow (leg) [kg/s]

(20) m.sub.0 Design mass flow (leg) [kg/s]

(21) The time-dependent correction term t.sub.corr(T) in Equation (1) includes the delay behavior of the surface heater/cooler determined by the thermal storage masses in the event of a step change in the load or setpoint.

(22) The described method for return/room temperature regulation also enables the individual room temperature regulation to be precisely guaranteed, even when there is no suitable place for mounting room temperature sensors. As a result of the control method, it is possible, without additional outlay, to use the current energy demand of each consumer for the overall optimization of the system and to exchange or save (energy) data via a network for further use.

LIST OF REFERENCES

(23) 10 Underfloor heating/cooling system 11 Central regulator 12 Heat generator 13 Chiller 14 Return manifold 15 Flow manifold 16 Heat exchanger (pipe coil) 17 Room temperature sensor/thermostat 18 Flow temperature probe 19 Pump 20 3-way valve 21,22 Changeover device 23 Outside temperature probe 24 Individual room temperature regulation apparatus 25 Flow line 26 Return line 27 Surface heater/cooler (e.g. underfloor heater) or heat exchanger 28 Flow sensor 29 Flow temperature sensor 30 Return temperature sensor 31 Control unit (program code) 31a Assignment part 31b Regulator part 32 Setpoint device 33 Base layer 34 Top layer M Motor m Mass flow QF Fluid heat flow Qh Room heat flow R1,Ri Room tRa,ti Room temperature tF Fluid temperature tFb Floor temperature tV Flow temperature tR Return temperature T Time V1,Vi Control valve