JP5705332B2 - Instant water heater - Google Patents

Description

  The present invention relates to an instantaneous water heater having a heat exchanger for heating a flowing liquid, wherein the instantaneous water heater includes an upper water inlet for connecting a cold water line, and a hot water line. And a control unit for adjusting or controlling the temperature of the liquid.

  The invention further relates to a method of operating such an instantaneous water heater having a heat exchanger for heating the flowing liquid.

  Instantaneous water heaters are used, for example, to heat water at home. Here, water is supplied to the instantaneous water heater via a cold water pipe, heated by a heat exchanger inside the instantaneous water heater, and sent out via a hot water pipe. This heat exchanger can be heated directly or via a secondary circuit. The term clean water should be understood as generic and includes, for example, drinking water.

  In order for the instantaneous water heater to operate normally, it is necessary to correctly connect the hot water pipe and the cold water pipe, that is, the cold water pipe to the water inlet and the hot water pipe to the It must be connected to the exit. In general, the heat supply to the heat exchanger is controlled depending on the delivery amount, and this delivery amount is detected by a flow-through sensor. However, the flow-through sensor only works satisfactorily if the intended flow-through direction through the heat exchanger is observed, i.e. the cold water line is at the water inlet and the hot water line is at the water outlet. Only when connected to the part. If these connections are mistaken, a measurement error of the delivered liquid can occur. It is also possible that the flow-through sensor described above does not output any signal, i.e. it cannot be determined whether or not liquid is delivered.

  Therefore, in the conventional instantaneous water heater, for normal operation, it is necessary to correctly connect the cold water pipe to the water outlet and the hot water pipe to the hot water inlet. If the connection is mistaken, it is generally impossible to deliver a heated liquid, for example hot water.

  An object of the present invention is to enable an instantaneous water heater to operate even when the above connection is mistaken.

  This object is achieved according to the invention by an instantaneous water heater having the characteristic configuration according to claim 1. Advantageous embodiments are described in the dependent claims.

  By placing a temperature sensor at the water inlet, the chilled water line is located at the water outlet or the water inlet without depending on the flow direction of the liquid through the heat exchanger, and Correspondingly, the heated liquid can be delivered without depending on whether the hot water pipe is arranged at the water inlet or the water outlet. The temperature change at the inlet of the water supply can be estimated by delivering the liquid or exiting by opening the cock. Such water delivery is also referred to as opening. If the temperature sensor indicates a rise in temperature at the water inlet, this means that a hot water line is connected to the water inlet, that is, heat exchange in the direction of flow from the water outlet to the water inlet. It shows that it passes the vessel. Therefore, adjustment or control of the temperature of the delivered liquid or heat exchanger is performed depending on the actual temperature measured at the water inlet. Since the normal operation set in the case of the flow direction from the water inlet to the water outlet can be turned off at this time, the instantaneous water heater is operated in an error operation.

  In general, a temperature sensor is disposed at the water outlet. Such a temperature sensor at the water discharge outlet is used when the hot water pipe and the cold water pipe are correctly connected, that is, in the case of the direction of flow from the water inlet to the water outlet. It is used to detect the actual temperature in the line and thus to control or regulate the heat transferred to the liquid by the heat exchanger. Error identification is further improved by a temperature sensor at the water outlet. By comparing the temperatures at the water inlet and the water outlet, the information about whether the chilled water pipe is connected to the water inlet or the water outlet is relatively reliable Obtained by sex. If the temperature at the water inlet is higher than the temperature at the water outlet, the heat exchanger is operated in an error operation because the above connection is mistaken.

  Advantageously, a through-flow sensor is arranged at the water inlet and / or water outlet. Such flow-through sensors are provided in many conventional instantaneous water heaters, where the flow rate is determined by the flow-through sensor, which controls the amount of heat transferred to the liquid by the heat exchanger. Used for. Such a through-flow sensor generally has high reliability in only one through-flow direction. In the present invention, the direction dependency of the through-flow sensor is that the cold water pipe is correctly connected to the water inlet. And it can utilize also in order to identify whether a warm water pipe line is correctly connected to the water outlet part. If the above-mentioned flow sensor does not send a signal despite the temperature rise at the water inlet, i.e. if the delivery is not signaled, this momentary water heater is clearly misconnected, The control of the liquid to be delivered must be activated with an error action which is dependent on the temperature at the water inlet.

  In one advantageous embodiment, the heat exchanger has a secondary circuit with a pump and a heat source that can be controlled by the control unit. With this secondary circuit and pump, the heat generated by the heat source enters the heat exchanger where it is transferred to the liquid so that the liquid can be heated and delivered. This heat source can have different configurations, for example it can be formed as a gas combustor, an oil combustor or as an electric heating element. It is also conceivable to form the secondary circuit as part of a central heating system, for example.

The control unit preferably has a storage device, which can store the following states. That is,
0: Check required 1: Normal operation 2: Error operation can be stored, and the operation of the instantaneous water heater is performed depending on this stored state. One byte is required to store each state, which has the advantage of being less error-prone than storing with a simple one bit. Before the first installation or initial start-up of the instant water heater, it is stored in the storage device that a check is necessary. This guarantees that each time a new connection is made, a check is made to see if the hot water conduit is properly connected to the water outlet and the cold water conduit is correctly connected to the water inlet. It is. If this check is yes, the instantaneous water heater operates in normal operation and this state is stored in the storage device. In normal operation, the user can make various settings, for example, the instant water heater is operated in the eco mode or the comfort mode. In eco mode, to save energy, the heat exchanger can be allowed to cool to a significant degree when liquid is not discharged by the tap. On the other hand, in the error operation, that is, when the hot water pipe is connected to the water inlet and the cold water pipe is connected to the water outlet, the operation in the eco mode cannot be performed. This is because the error operation requires a repeated check of the connection, which is possible only when the heat exchanger is operating in the operating temperature range. Other setting options by the user may also be limited in error behavior.

  Advantageously, the control unit is designed such that when the hot water line is connected to the water inlet, warm liquid is transferred to the water inlet, and in some cases the display indicates an error action, In this case, in particular, the temperature of the heat exchanger is raised, kept constant or controlled depending on the temperature at the water inlet. In other words, even when the above connection is mistaken, this makes it possible to operate the instantaneous water heater sufficiently. By providing a corresponding indicator in this case, the plumber can identify and remove the cause of the error relatively quickly. However, it is not necessary to stop the water heater until this error is removed. Rather, this is possible even if the operation is limited.

  This object is achieved according to the invention by the method described in the characterizing part of claim 6.

  The flow direction of the liquid is obtained by a heat exchanger, and the control of the actual temperature of the liquid to a preset target temperature is performed depending on the flow direction. In other words, this instantaneous water heater has a through-flow direction from the water inlet to the water outlet, that is, even when the hot water pipe and the cold water pipe are correctly connected, It can also be operated in the reverse flow direction leading to the part. In this case, different control parameters can be used depending on the flow direction. For example, the target temperature can be fixed in advance in the case of the flow direction from the water outlet to the water inlet, whereas the target temperature can be set to a fixed value in the correct flow direction from the water inlet to the water outlet. This target temperature can be changed by the user, for example, by selecting the eco mode.

  Advantageously, the above flow direction is determined by measuring the temperature at the water inlet, possibly with respect to measuring the temperature at the water outlet and / or at the water inlet or at the water outlet. Required by the once-through sensor. The temperature rise at the water inlet is a sign that the hot water pipe is connected to the water inlet, that is, the flow direction is from the water outlet to the water inlet. However, this error identification can further increase the reliability by detecting the temperature at the water outlet. When the temperature at the upper water inlet portion rises with respect to the temperature at the upper water outlet portion when the liquid is delivered, the flow from the upper water outlet portion to the upper water inlet portion is clearly performed. Direction-dependent flow-through sensors can also be used to determine the flow-through direction. However, in this case, in order to control the actual temperature of the liquid to be delivered, it is also necessary to detect the temperature at the water inlet.

  Preferably, the temperature T1 is measured at the water inlet and the temperature T2 is measured at the water outlet, and the temperature T2 is controlled to the target temperature when the temperature T2 is higher than the temperature T1, and the temperature T1 is higher than the temperature T2. When it is high, T1 is controlled to the target temperature. That is, here, both the temperature at the water inlet and the temperature at the water outlet are detected. This control is always based on the detected higher temperature, which provides reliable information about the direction of flow through the heat exchanger. When the temperature T2 at the upper water outlet is higher than the temperature T1 at the upper water inlet, it is in a normal operating state, whereas the temperature T1 at the upper water inlet is higher than the temperature T2 at the upper water outlet. In error operating state. Depending on whether it is in a normal operation state or an error operation state, the control unit can be operated by different programs or in different modes.

It is particularly advantageous here to store one of the following three states in the storage device: That is,
0: Check required 1: Normal operation 2: Stores one of the error operation states, and sets the storage device to “0” when the instant water heater is initialized and / or after a relatively long stop time However, especially in error operation, the check of the flow direction is repeated. In the shipping state, that is, before the initial initialization or the first start-up of the instantaneous water heater, it is stored in the storage device that a check is necessary. As a result, at the first start-up, it is checked whether the hot water pipe and the cold water pipe are correctly connected. For this purpose, the heat exchanger is heated, and the temperature at the water inlet is detected. In some cases, the temperature at the water outlet is additionally detected and compared with the temperature at the water inlet. It is also conceivable to detect whether or not the liquid is delivered using a flow-through sensor. When the temperature at the water inlet is higher than the temperature at the water outlet, it is stored in the storage device that the instantaneous water heater is operated in an error operation. However, when the temperature at the tap water outlet rises above the temperature at the tap water inlet, it is stored in the storage device that the instantaneous water heater is operated in normal operation. In the error operation, the user setting can be performed only in a limited manner. For example, since the operation in the eco mode is not possible, the heat exchanger is not excessively cooled. In the error operation, the flow direction is newly checked periodically.

  In error operation, the temperature of the heat exchanger is preferably maintained between the upper boundary temperature and the lower boundary temperature. This can be done, for example, by fuzzy control.

  In error operation, a higher target value is advantageously used than in normal operation. This ensures that a sufficiently warm liquid is delivered from the heat exchanger to the hot water line, even if the cold water line and the water line are not properly connected. By increasing the target value, error identification can be improved at the same time. This is because increasing the target value leads to higher temperatures when the liquid is delivered.

  In the following, the invention will be described in detail on the basis of preferred embodiments in connection with the drawings.

1 is a schematic diagram showing an instantaneous water heater. 2 is an example flow of a method according to the invention.

  In FIG. 1, an instantaneous water heater 1 having a heat exchanger 2 is schematically shown, and the heat exchanger 2 has an upper water inlet portion 21 and an upper water output portion 22. The heat energy formed by the heat source 52 is supplied to the heat exchanger 2 through the secondary circuit 5. Transmission of heat energy from the heat source 52 to the heat exchanger 2 is performed by a liquid such as water conveyed by the pump 51.

  When correctly installed, a cold water pipe 31 is arranged at the water inlet 21 and a hot water pipe 32 is arranged at the water outlet 22. The through flow passing through the heat exchanger 2 flows from the water inlet 31 to the water outlet 32. In the heat exchanger 2, heat energy is transmitted to the liquid, that is, the liquid is heated. The liquid is heated and sent to the hot water pipe 32. In the following, it is assumed that water is used as the liquid, but it is also possible to use another liquid.

  The heat energy transmitted from the heat exchanger 2 to the water is controlled by the control unit 4. Generally, the delivery rate is detected by the flow-through sensor 8, and the above control determines how much heat must be transferred by the heat exchanger 2 depending on the delivery rate. The heat energy provided by the secondary circuit 5 is supplied accordingly. Such control can satisfy the requirements when the cold water pipe and the hot water pipe are correctly connected, that is, in the case of a through-flow direction from the water inlet to the water outlet. The target temperature can be controlled by controlling using the temperature sensor 7 disposed at the water outlet section 22.

  However, if the flow direction is reversed, that is, if the cold water pipe 31 is mistakenly connected to the water outlet 22 and the hot water pipe 32 is connected to the water inlet 21, the flow sensor 8 no longer outputs a signal. The temperature sensor 7 at the water outlet 22 always shows a constant temperature. That is, only the temperature of the cold water supplied is shown. As a result, in this case, the hot water cannot be controlled and sent out.

  In the present invention, the temperature sensor 6 is disposed at the water inlet portion 21. Such a temperature sensor 6 has a further monitoring function when the connection is made correctly, that is, in the case of a through-flow direction from the water inlet portion 21 to the water outlet portion 22. That is, the water heated in advance at the water inlet 21 is detected. This is because, for example, preheating by solar power is confirmed. When the water temperature at the water inlet 21 is higher than the water temperature at the water outlet 22, the instantaneous water heater 1 or its heat source 52 is not activated. Furthermore, the temperature sensor 6 can be used to optimize the water temperature at the water outlet 22 by predictive control, that is, taking into account the water inlet temperature. However, even when the hot water pipe is connected to the water inlet 21, that is, even when the instantaneous water heater 1 flows through by mistake, this sensor further ensures the flow direction. And the target temperature of the liquid to be delivered can be controlled.

  When correctly connected, that is, when the cold water pipe 31 is connected to the water inlet 21 and the hot water pipe 32 is connected to the water outlet 22, a normal operation is performed. The error operation is performed when the heat exchanger 2 is operated in the opposite direction, that is, when the cold water pipe 31 is connected to the water outlet section 22 and the hot water pipe 32 is connected to the water inlet section 21. Occurs. Whether or not an error operation has occurred can be indicated on the display 9, whereby, for example, a plumber can check whether the hot water pipe 32 and the cold water pipe 31 are correctly connected to the heat exchanger 2. Can be identified immediately.

  FIG. 2 schematically shows a possible flow of the method according to the invention. After initial installation, i.e. after the initial start-up of the instantaneous water heater 1 or after a relatively long interruption of operation, the heat exchanger 2 is first heated. At the next hot water delivery, the temperature at the water inlet 21 is detected. In some cases, the heat source 52 can further supply heat, and at this time, the temperature at the water inlet 21 is continuously detected. The temperature at the tap water inlet 21 before starting the heat source 52 is compared with the temperature detected later. When the temperature rises, a flow is made in the direction from the water outlet part 22 to the water inlet part 21, that is, an error operation occurs. In accordance with this, warm water is sent out from the water inlet 21 and the actual temperature at the water inlet 21 is controlled. If the temperature at the water inlet 21 is low despite the heat source 52 supplying heat energy to the heat exchanger 2, the cold water line 31 and the hot water line 32 are correctly connected, Since the normal operation of sending warm water to the water outlet 22 is performed, the temperature at the water outlet 22 is controlled to the target temperature.

  Heating of the instantaneous water heater 1 at the first start is performed regardless of which mode the instantaneous water heater 1 is set to. That is, for example, it is performed regardless of whether or not the eco mode in which the heat exchanger 2 is heated only when requested is selected.

  When temperature detection is performed at the water outlet 22 in addition to temperature detection at the water inlet 21, the flow direction can be determined relatively easily by comparing these two temperatures. If the temperature at the water outlet 22 exceeds the temperature at the water inlet 21 during the delivery of the liquid, the instantaneous water heater is operating normally. On the other hand, when the temperature at the water inlet 21 is higher than the temperature at the water outlet 22, the instantaneous water heater 1 performs an error operation. This error identification can be improved by additionally providing a flow-through sensor.

  An error operation can also be assumed when cooling is not performed at the water inlet 21 during the delivery of the liquid, that is, when the temperature does not drop.

  The method according to the invention can easily be additionally implemented and can also be retrofitted to existing instantaneous water heaters. This method is effective only when the cold water pipe 31 and the hot water pipe 32 are not properly connected. Even when the connection is not correctly performed, it is possible to deliver the heated liquid with high reliability, that is, the instantaneous water heater 1 is operated in an error operation. At the same time, this error can be identified very easily, so that the correction can be carried out very quickly and therefore only a small cost is incurred.

  The check of the flow direction by heating the instantaneous water heater 1 does not depend on the set mode, that is, for example, does not depend on whether the instantaneous water heater 1 is operating in the eco mode or the comfort mode. To be done. During an error operation, the temperature of the heat exchanger 2 is maintained between the lower boundary temperature and the upper boundary temperature. That is, the heat exchanger 2 is always maintained at a high temperature. During normal operation, for example, adjustment to the eco mode is possible, and the heat exchanger 2 can be significantly cooled to save energy.

  Conventionally, the heat energy transmitted from the heat exchanger 2 to the liquid to be delivered is controlled depending on the delivery amount, whereas in the present invention, the temperature at the water inlet 21 is detected. Even when the pipe line 31 and the hot water pipe line 32 are mistakenly connected, the temperature of the liquid to be delivered can be controlled.

Claims (12)

Instantaneous water heater (1) having a heat exchanger (2) for heating the flowing liquid,
The instantaneous water heater (1) has an upper water inlet (21) for connecting a cold water pipe (31) and an upper water outlet (22) for connecting a hot water pipe (32). And
A temperature sensor (7) is disposed at the water outlet (22);
In the instantaneous water heater (1) provided with a control part (4) for controlling or adjusting the temperature of the liquid,
Another temperature sensor (6) is arranged in the tap water inlet (21),
The heat exchanger (2) is heated by a heat source (52);
The temperature rise is caused by continuously detecting the temperature at the water inlet (21) by the another temperature sensor (6), or
- the temperature of the liquid in the clean water inlet detected by the further sensor (6) (21), above the temperature of the liquid in said clean water outlet portion detected by the temperature sensor (7) (22) If you have
It is determined that there is a through-flow in the direction from the water outlet portion (22) to the water inlet portion (21), and operates with an error operation to send warm water to the water inlet portion (21). The heat exchanger (2) is configured as follows,
Instantaneous water heater (1) characterized by that. In the instant water heater according to claim 1,
A flow-through sensor (8) is arranged in the water inlet part (21) and / or the water outlet part (22),
Instantaneous water heater characterized by that. In the instant water heater according to claim 1 or 2,
The heat exchanger (2) is connected to a secondary circuit having a pump and a heat source that can be controlled by the controller (4).
Instantaneous water heater characterized by that. In the instant water heater according to any one of claims 1 to 3,
The control unit (4) has a storage device, and the storage device has the following states:
0: Check required 1: Normal operation 2: Error operation can be stored,
The action is performed depending on the stored state,
Instantaneous water heater characterized by that. In the instant water heater according to any one of claims 1 to 4 ,
Or temperature before Symbol heat exchanger (2) is increased, the control unit so as to control in dependence on the temperature in either held constant, or the tap water inlet (21) (4) is designed Being
Instantaneous water heater characterized by that. In the instant water heater according to claim 5,
The control unit (4) is designed so that the indicator (9) displays an error operation when the hot water pipe (32) is connected to the water supply inlet (21).
It is characterized by an instantaneous water heater. In the method for operating the instantaneous water heater according to any one of claims 1 to 6,
The flow direction of the liquid is determined by the heat exchanger,
Depending on the flow direction, the actual temperature of the liquid is controlled to a preset target temperature.
A method characterized by that. The method of claim 7 , wherein
A flow direction is determined in connection with the measurement of the temperature at the water outlet and / or by a flow sensor at the water inlet or at the water outlet.
A method characterized by that. The method according to any one of claims 6 to 8 , wherein
Measure the temperature (T1) at the water inlet and the temperature (T2) at the water outlet,
When the temperature (T2) is higher than the temperature (T1), the temperature (T2) is controlled to a target temperature, whereas when the temperature (T1) is higher than the temperature (T2), the temperature (T2) is controlled. T1) is controlled to the target temperature,
A method characterized by that. The method according to any one of claims 6 to 9 , wherein
Maintaining the temperature of the heat exchanger between a lower boundary temperature and an upper boundary temperature;
A method characterized by that. The method of claim 10 , wherein
Maintaining the above temperature during error operation,
A method characterized by that. 12. The method according to any one of claims 6 to 11 , wherein
Use a higher target value during error operation than during normal operation.
A method characterized by that.

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