Heating device and method for operating a heating device

Abstract

A heating device, including at least one heating unit, which is configured to heat at least one fluid; at least one fluid supply line, which is provided for supplying the fluid to the heating unit for heating; at least one fluid discharge line, which is provided for discharging the fluid from the heating unit after the heating; and a control and/or regulating unit, which is configured to operate the heating unit in a pulsed manner, in at least one operating state, in order to set a particular temperature. The heating device includes a valve unit, which is configured to mix the fluid in the fluid discharge line with fluid from the fluid supply line, upstream from an outlet.

Claims

1. A heating device, comprising: at least one heater configured to heat at least one fluid; at least one fluid supply line which supplies the at least one fluid to the at least one heater for heating; at least one fluid discharge line which discharges the at least one fluid from the at least one heater after the heating; a control and/or regulator which operates the at least one heater in a pulsed manner in at least one operating state to set a particular temperature; and a valve unit which mixes the at least one fluid in the fluid discharge line with fluid from the fluid supply line, upstream from an outlet, wherein the control and/or regulator is configured to control the valve unit at least substantially synchronously with a pulsed operation of the at least one heater by generating and/or outputting a control pulse for controlling the valve unit simultaneously to generating and/or outputting a control pulse for controlling the at least one heater.

2. The heating device as recited in claim 1, wherein the control and/or regulator is configured to control the valve unit so that the at least one fluid has an at least substantially uniform outlet temperature.

3. The heating device as recited in claim 1, wherein the control and/or regulator is configured to increase a flow rate of fluid through the valve unit during the pulsed operation, in response to increasing heating power of the at least one heater.

4. The heating device as recited in claim 1, wherein the control and/or regulator is configured to decrease a flow rate of fluid through the valve unit during the pulsed operation, in response to decreasing heating power of the at least one heater.

5. The heating device as recited in claim 1, wherein the valve unit includes at least one bypass valve, which is situated fluidically in parallel with the at least one heater.

6. The heating device as recited in claim 1, wherein the valve unit includes at least one mixing valve, which is situated fluidically in the fluid discharge line.

7. The heating device as recited in claim 1, wherein the control and/or regulator is configured to operate the at least one heater in a pulsed manner, such that the at least one fluid is heated to a temperature, which lies above a selected outlet temperature of the at least one fluid.

8. A continuous-flow heater, including at least one heating device, the at least one heating device comprising: at least one heater configured to heat at least one fluid; at least one fluid supply line which supplies the at least one fluid to the at least one heater for heating; at least one fluid discharge line which discharges the at least one fluid from the at least one heater after the heating; a control and/or regulator which operates the at least one heater in a pulsed manner in at least one operating state to set a particular temperature; and a valve unit which mixes the at least one fluid in the fluid discharge line with fluid from the fluid supply line, upstream from an outlet, wherein the control and/or regulator is configured to control the valve unit at least substantially synchronously with a pulsed operation of the at least one heater by generating and/or outputting a control pulse for controlling the valve unit simultaneously to generating and/or outputting a control pulse for controlling the at least one heater.

9. A method for operating a heating device, the heating device including at least one heater which is configured to heat at least one fluid, at least one fluid supply line which supplies the at least one fluid to the at least one heater for heating, at least one fluid discharge line which discharges the at least one fluid from the at least one heater after the heating, and a control and/or regulator which is configured to operate the heater in an at least partially pulsed manner, in at least one operating state, in order to set a particular temperature, the method comprising: mixing the at least one fluid in the fluid discharge line with fluid from the fluid supply line, upstream from an outlet, wherein the control and/or regulator is configured to control a valve unit at least substantially synchronously with a pulsed operation of the at least one heater by generating and/or outputting a control pulse for controlling the valve unit simultaneously to generating and/or outputting a control pulse for controlling the at least one heater.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages are derived from the description below of the figures. Two exemplary embodiments of the present invention are shown in figures. The figures and the description herein include numerous features in combination. One skilled in the art will advantageously consider the features individually, as well, and integrate them to form useful, further combinations.

(2) FIG. 1 shows a schematic block diagram of a heater including a heating device.

(3) FIG. 2 shows a graphical representation of temperature curves of the heating device and fluid flow rate curves of a valve unit.

(4) FIG. 3 shows a schematic block diagram of a heater including an alternative heating device.

(5) FIG. 4 shows a schematic block diagram of a heater including a further alternative heating device.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

(6) FIG. 1 shows a schematic block diagram representation of a heater 34a exemplarily taking the form of a continuous-flow heater. Heater 34a includes a heating device 32a. Heating device 32a includes a heating unit 10a. Heating unit 10a is configured to heat a fluid. In the present case, heating unit 10a is configured to heat water. To that end, heating unit 10a includes a heating module 36a. Heating module 36a takes the form of a gas burner module. However, as an alternative, it is also conceivable for the heating unit to be configured to heat a different fluid, such as a refrigerant and/or a heating medium. Heating device 32a includes a fluid supply line 12a, which is provided for supplying the fluid to heating unit 10a for heating, and a fluid discharge line 14a, which is provided for discharging the fluid from heating unit 10a after the heating.

(7) Heating module 36a includes a suction unit 38a, which is provided for drawing in combustion air and fuel. To that end, suction unit 38a is connected to a first supply line 40a for combustion air, and to a second supply line 42a for fuel. Heating module 36a further includes a burner 44a. A combustion-air/fuel mixture is supplied to burner 44a by suction unit 38a. Burner 44a is configured to burn the combustion-air/fuel mixture in at least one operating state. In this context, burner 44a is configured to produce a heating flame.

(8) In addition, heating unit 10a includes a heat exchanger 46a. Heat exchanger 46a is situated in the vicinity of the heating flame. Heat exchanger 46a is configured to transfer thermal energy from heating module 36a to the fluid. An unheated fluid, in particular, water, is supplied to heat exchanger 46a via fluid supply line 12a. Heated fluid is directed out of heat exchanger 46a via fluid discharge line 14a.

(9) Furthermore, heating unit 10a includes an exhaust gas module 48a. Exhaust gas module 48a takes the form of a chimney. Exhaust gas module 48a is provided for removing exhaust gases. To that end, exhaust gas module 48a is connected to an exhaust gas outlet 50a.

(10) In addition, heating device 32a includes a supply unit 52a. Supply unit 52a is configured to supply the unheated fluid to heat exchanger 46a and/or heater 34a. To that end, supply unit 52a includes a fluid inlet 54a. Fluid inlet 54a is connected to fluid supply line 12a. In addition, supply unit 52a includes a main valve 68a, which is positioned in fluid supply line 12a. Furthermore, heating device 32a includes a discharge unit 56a. Discharge unit 56a is configured to remove the heated fluid from heat exchanger 46a and/or heater 34a. For that purpose, discharge unit 56a includes an outlet 20a, which is connected to fluid discharge line 14a.

(11) Heating device 32a also includes a plurality of sensors 60a, 62a, 64a, 66a. A first sensor 60a takes the form of a flow rate sensor. A second sensor 62a takes the form of a first temperature sensor. Second sensor 62a is provided for detecting a temperature of the fluid directly downstream from fluid inlet 54a. A third sensor 64a takes the form of a second temperature sensor. Third sensor 64a is provided for detecting a temperature of the fluid directly downstream from heat exchanger 46a. A fourth sensor 66a takes the form of a third temperature sensor. Fourth sensor 66a is provided for detecting a temperature of the fluid directly upstream from outlet 20a.

(12) In addition, heating device 32a includes a control and/or regulating unit 16a. Control and/or regulating unit 16a is configured to control an operation of heating device 32a. To that end, control and/or regulating unit 16a includes an arithmetic unit, a storage unit, and an operating program, which is stored in the storage unit and is configured to be executed by the arithmetic unit. In addition, control and/or regulating unit 16a is configured to set and/or supply the requested heating power. For that purpose, control and/or regulating unit 16a has an electrical connection with sensors 60a, 62a, 64a, 66a. In addition, control and/or regulating unit 16a has an electrical connection with burner 44a and main valve 68a. Control and/or regulating unit 16a is configured to control burner 44a and main valve 68a. In one operating state, control and/or regulating unit 16a is configured to operate heating unit 10a, in particular, heating module 36a, in a pulsed manner, in order to set a particular temperature.

(13) In addition, heating device 32a includes a valve unit 18a. Valve unit 18a is configured to mix the fluid in fluid discharge line 14a with fluid from fluid supply line 12a, upstream from outlet 20a. Valve unit 18a includes a bypass valve 28a, which is connected fluidically in parallel with heating unit 10a. First sensor 60a and main valve 68a are situated fluidically in back of a branching-off point 70a from fluid supply line 12a to a bypass line 72a connected to bypass valve 28a. Control and/or regulating unit 16a is configured to control valve unit 18a in such a manner, that a uniform outlet temperature 22a of the fluid sets in (cf. FIG. 2).

(14) FIG. 2 shows a pulsed operating mode. In this context, a time is represented on an abscissa axis 74a. An ordinate axis 76a is represented as a magnitude axis. In the present case, in the operating state, control and/or regulating unit 16a is configured to operate heating module 36a in a pulsed manner, in order to set a particular temperature. Control and/or regulating unit 16a is configured to operate heating unit 10a in a pulsed manner, such that the fluid is heated to a temperature, which lies above a selected outlet temperature 22a of the fluid. A curve 78a indicates the periodically fluctuating temperature of the fluid immediately downstream from heat exchanger 46a, measured by third sensor 64a. The fluid in fluid discharge line 14a is mixed with fluid from fluid supply line 12a, directly upstream from outlet 20a. In this context, an inflow amount of the fluid from fluid supply line 12a is adjusted with the aid of valve unit 18a. A second curve 80a indicates the temperature of the fluid immediately downstream from fluid inlet 54a, measured by second sensor 62a. Control and/or regulating unit 16a is configured to control valve unit 18a at least substantially synchronously with the pulsed operation of heating unit 10a. Control and/or regulating unit 16a is configured to increase a flow rate of fluid 24a through valve unit 18a during pulsed operation, in response to increasing heating power of heating unit 10a, and to reduce flow rate of fluid 24a through valve unit 18a again, during pulsed operation, in response to decreasing heating power of heating unit 10a. A third curve 82a shows the flow rate of fluid 24a through valve unit 18a changing synchronously with the temperature of the fluid immediately downstream from heat exchanger 46a. A fourth curve 84a shows the resulting uniform outlet temperature 22a of the fluid by fourth sensor 66a.

(15) Further exemplary embodiments of the present invention are shown in FIGS. 3 and 4. The following descriptions and the figures are mainly limited to the differences between the exemplary embodiments; regarding component parts labeled identically, in particular, with regard to component parts having the same reference numerals, in general, reference may also be made to the figures and/or to the description of the other exemplary embodiments, in particular, of FIGS. 1 and 2. To distinguish the exemplary embodiments, the letter, a, follows the reference numerals of the exemplary embodiment in FIGS. 1 and 2. In the exemplary embodiments of FIGS. 3 and 4, the letter, a, is replaced by the letters, b through c.

(16) FIG. 3 shows an alternative embodiment of a heating device 32b. Heating device 32b includes a valve unit 18b. Valve unit 18b is configured to mix a fluid in a fluid discharge line 14b with fluid from a fluid supply line 12b, upstream from an outlet 20b. Valve unit 18b includes a bypass valve 28b, which is connected fluidically in parallel with a heating unit 10b. A first sensor 60b, which takes the form of a flow rate sensor, and a main valve 68b, are situated fluidically upstream from a branching-off point 70b from fluid supply line 12b in a bypass line 72b connected to bypass valve 28b.

(17) FIG. 4 shows a further alternative embodiment of a heating device 32c. Heating device 32c includes a valve unit 18b. Valve unit 18c is configured to mix a fluid in a fluid discharge line 14c with fluid from a fluid supply line 12c, upstream from an outlet 20c. Valve unit 18c includes a mixing valve 30c, which is situated fluidically in fluid discharge line 14c. A first sensor 60c, which takes the form of a flow rate sensor, and a main valve 68c, are situated fluidically upstream from a branching-off point 70c from fluid supply line 12c in a bypass line 72c connected to mixing valve 30c.