1295723 【發明所屬之技術領域】 本發明係將電熱水器之加熱器進行加熱時，所偵、測到 電流供給的變化，與正常加熱時之電流的變化相互比較， 以獲得電流供給時是否發生異常狀況的判斷，進而提供為 對加熱器之加熱的繼續或停止之依據。 【先前技術】 一般電熱水器之儲熱桶内除了裝設有加熱器，並在加 熱器的中間再設有感溫器，使能藉由感溫器對儲熱桶内的 水進行溫度的偵測，而其加熱的控制方式如第一圖所示， 係當電源開啟後，該感溫器就會偵測水溫是否已達預先設 定的水溫上限溫度，如果水溫未達預設的上限溫度時，就 會令加熱器開始進行加熱，直到水溫達到預設的上限溫度 後，就會令加熱器停止加熱，然後又待水溫下降到低於預 設的上限溫度的誤差範圍值外時，則又會再度令加熱器進 行加熱，如此反覆執行，使得儲熱桶内的水能夠保持在預 定的水溫範圍内，以提供適當的熱水給使用者，此即為一 般所謂的「正常加熱程序」；同時為了能夠讓使用者在短 時間内享用熱水，加熱器必須被供給很大的電流，才能讓 加熱器本身在非常短的時間内產生高溫，進而將水加熱至 預定的溫度，不過因加熱器是整個浸泡於水中，水會很快 地把加熱器的高溫吸收帶走，令加熱器不致於因高溫而燒 毁，這也就是熱交換之加熱原理。 可是，上述的熱水器的加熱情況，係屬於在正常的狀 況下，所執行的正常加熱程序，加熱器當然可以正常地運 5 1295723 作執行而不致於燒毁，但可能會有下列的狀況，必須藉由 其它程序來執行控制，例如： 1. 當儲熱桶内的水發生不足、或甚至完全沒有供水進 入桶内的情況，特別容易發生於首次安裝電熱水時，負責 安裝施工的人員在進行試機時，忘記先要把水引入儲熱桶 内、或者引入儲熱桶内的水根本不足，進而直接啟動電源 令加熱器對水加熱，在加熱器無法與水進行熱交換的狀況 下，此刻加熱器的溫度會在極短的時間内急驟上升，進而 造成加熱器的燒毁，就是發生了所謂的「空燒」現象，即 使試機人員即時發現而在加熱器尚未燒毁前就切斷電力， 該加熱器也可能發生折損，進而減短了加熱器使用壽命； 雖然目前都有在電熱水器中加裝了過電流保護繼電器，不 過仍然還是無法避免加熱器因高溫所產生的折損現象。 2. 加熱器雖然一直都在正常的加熱控制程序下運作， 但由於水中含有碳酸約、镁等灰白色的礦物質，加熱器經 長期的加熱作用下，會在其表面不斷累積附著相當厚度的 水垢，此時不但會影響加熱的效能，嚴重者更可能令水垢 將加熱器連同感溫器整個幾乎被包覆起來，造成中間的感 熱器被包覆在内部後，而無法真正感測到儲水桶内之水的 溫度外，如果加熱器加熱時，包覆住加熱器之水垢吸收所 含的水份極少，所以水垢會很快地被加熱而達到預設的水 溫上限，進而在非常短的時間内，加熱器就會停止加熱， 可是儲熱桶内的水卻幾乎完全無法被加熱狀況下，幾乎根 本不可能讓水加熱至所預設的水溫，導致喪生了加熱的功 6 1295723 能，即使加熱n水垢沒有完全包覆住加熱器，但 所附著的水垢已累積相#的厚度時，目前所知的 地根本無法自動價測到這樣的情況，使用益、^ 7益 電=内部之加熱器的情況，所以加熱器的到 漸文差日守’使用者根本無法獲知外，進而力逐 與浪費。 、成包力上虛耗 當然，目前亦有以债測加熱器加熱時，並 的變化來判斷，進而來控制埶二/皿又斤產生 空燒广現象發生’獨以溫度變二為':的=止「 有其目點存在，也就是當加熱器被施以大士，'豕，仍 低溫變成高溫而進行加熱’但是如果儲會由 況下’加熱器由低溫變成高溫，再由高溫=热水的狀 的臨界上限溫度時（即被燒毁的溫度），^二加熱器 -段時間才能達到，但若會發生空燒的現耗費 以偵測得知，而無須等待到加熱器溫度 ^早就可 ’如此反而容易發生延遲的情況，導致 ^程度 止加熱的時候’該加熱器雖然沒有 ：：電佯 經受損。 么但也可能已 另外’若當加熱器表面所附著的水垢 當的厚度時，#加熱效能會逐漸變差，但已、〜以貝到相 熱時所產生的溫度變化來判斷的話，由於：=:熱器加 序裡，溫度根太不合卜曰二+ 吸正吊的加熱程 也根本無法庐知加二了力1^器的臨界上限溫度，所以 【發明内容;加熱以否已經被水垢嚴攻的包覆。 7 1295723 緣是，為了改善前述加熱器表面積垢後，導致感溫器 無法正確偵測到加熱的效能、及即時在發生空燒更早之前 就被偵測而斷電等問題，本發明係採電流偵測的方式，而 在加熱器實際執行加熱時所發生的電流變化，與正常加熱 狀態時的電流變化相較，進而做為判斷加熱器之加熱與否 的依據者。 因此，藉由上述的手法，令加熱器在正常的狀況下執 行正常的加熱程序，但若實際加熱後之電流與正常之電流 變化比較，發生在誤差範圍外時，就會令加熱器停止加熱 ，並提供異常狀態的表示來警告使用者，並增高電熱水器 之使用的安全性。 又，上述偵測電流變化之方式，不但反應速度快且又 精準，不但可以在加熱器加熱後的溫度尚未昇高至一定程 度時，就能即時地切斷電源來保護加熱器，以防加熱器因 高溫而受折損者。 其次，上述偵測電流變化之方式，在加熱器表面附著 水垢而受到嚴重的包覆時，雖無立即危險會發生，仍能由 加熱器之耗電流的變化而獲知，來提醒使用者的注意及更 換，進而保持電熱水器最佳的效能及避免電力不必要的虛 耗浪費。 是以，本發明可藉由下列的實施例並配合附圖，而獲 得充分的了解，並據以實施： 【實施方式】 請請參閱第二圖所示，本發明係在電熱水器的加熱器 8 1295723 控制電路上設有個電流偵測器或偵測電路，使能偵測得知 加熱器在加熱時所產生之電流的變化，進而藉由此電流變 化的數據，提供做為加熱器執行加熱與否的判斷依據，同 時本發明的控制手法如下： 1. 首先在開啟電熱水器的電源後，進行儲熱桶内溫度 的偵測。 2. 如果儲熱桶内的溫度高於預設的低溫值時，則會令 加熱器執行一般正常的加熱程序。 3. 但如果儲熱桶内的溫度未達或低於預設的低溫值時 ，則會令加熱器進行加熱，並經過一段時間後，再令加熱 器停止加熱。 4. 然後上述加熱器實際加熱期間所發生的電流變化， 藉由電流感測器或電路偵測而得後，再與正常加熱狀態時 的電流變化相較，如果係在預定的誤差範圍内，即表示儲 熱桶内充滿了水而無加熱異常的狀況發生，則令加熱器進 行一般正常的加熱程序。 5. 但如果第3步驟之加熱器實際加熱期間所發生的電 流變化，與正常加熱狀態時的電流變化相較，如果係在預 定的誤差範圍外時，則表示可能空燒或加熱器表面水垢太 厚，造成加熱上的異常，進而令加熱器停止加熱，並同時 發出異常的訊號（可為燈號、顯示幕或聲響者），來提醒 或警告使用者。 因此，藉由上述之周而復始地不斷的偵測、比較，即 使當加熱器表面附著嚴重的水垢時，雖無立即的危險會發 9 1295723 生，仍能由加熱器之耗電流的變化而獲知，進而能隨時發 現到加熱情況是否有所異常，適時地提醒使用者，進行檢 查或維修，以保持電熱水器最佳的加熱效能與避免不必要 之電力的虛耗浪費外。 同時，以偵測電流變化之方式，不但反應速度快且又 精準，可以在加熱器加熱後的溫度，尚未昇高至一定相當 之程度時，就已經可由耗電流的變化而獲知，進而即時地 切斷電源來保護加熱器，以防加熱器因高溫而受折損，提 高電熱水器使用上的安全性，並防止電熱水器被嚴重地燒 毁。 儘管，上述的實施例已對本發明有較佳之具體化的揭 露與詳述，皆為熟悉該項技術人士者所能清楚了解，而其 所做的各種型式及方法局部的改變，應都是沒有脫離本發 明精神與範疇。 【圖式簡單說明】 第一圖係習知電熱水器之加熱控制方法的流程示意圖。 第二圖係本發明電熱水器預防空燒之方法的流程示意圖。 【主要元件符號說明】 101295723 [Technical Field According to the Invention] The present invention relates to detecting and measuring a change in current supply when a heater of an electric water heater is heated, and comparing with a change in current during normal heating to obtain an abnormality in current supply. The determination of the condition is in turn provided as a basis for the continuation or cessation of heating of the heater. [Prior Art] In addition to the heater installed in the heat storage bucket of the electric water heater, a temperature sensor is arranged in the middle of the heater to enable the temperature of the water in the heat storage bucket to be detected by the temperature sensor. Test, and the heating control method is as shown in the first figure. When the power is turned on, the temperature sensor detects whether the water temperature has reached the preset water temperature upper limit temperature, if the water temperature does not reach the preset value. When the upper limit temperature is reached, the heater will start to heat up, until the water temperature reaches the preset upper limit temperature, the heater will stop heating, and then the water temperature will drop to a value lower than the preset upper limit temperature. When it is outside, the heater will be heated again, so that the water in the heat storage bucket can be kept within a predetermined water temperature range to provide appropriate hot water to the user. This is generally called "Normal heating procedure"; at the same time, in order to allow the user to enjoy hot water in a short time, the heater must be supplied with a large current to allow the heater itself to generate high temperature in a very short time, thereby heating the water to The predetermined temperature, but because the heater is completely immersed in water, the water will quickly take away the high temperature absorption of the heater, so that the heater will not be burnt due to high temperature, which is the heating principle of heat exchange. However, the above-mentioned heating condition of the water heater belongs to the normal heating procedure performed under normal conditions, and the heater can of course be normally operated 5 1295723 for execution without burning, but the following conditions may be required, The control is performed by other procedures, for example: 1. When the water in the heat storage tank is insufficient, or even no water supply enters the barrel completely, it is particularly likely to occur when the first installation of the electric hot water is performed, and the person responsible for the installation and construction is proceeding. When testing the machine, forgetting to introduce water into the heat storage tank or introducing water into the heat storage tank is not enough, and then directly start the power supply to heat the heater to the water, in the case that the heater cannot exchange heat with water. At this moment, the temperature of the heater will rise sharply in a very short period of time, which will cause the heater to burn out. This is the so-called "empty burning" phenomenon, even if the tester immediately discovers and cuts the heater before it is burned. When the power is cut off, the heater may also be damaged, thereby shortening the service life of the heater; although it has been installed in the electric water heater Flow protection relay, However it is still unable to avoid breakage phenomenon due to heat generated by the heater. 2. Although the heater has been operating under normal heating control procedures, because the water contains grayish-white minerals such as carbonic acid and magnesium, the heater will accumulate a considerable amount of scale on its surface after long-term heating. At this time, not only will the heating performance be affected, but in severe cases, the scale will be almost covered with the heater together with the temperature sensor, so that the middle heat sensor is coated inside, and the water storage bucket cannot be truly sensed. In addition to the temperature of the water inside, if the heater is heated, the scale covered by the heater absorbs very little water, so the scale will be heated quickly to reach the preset upper limit of water temperature, which is very short. During the time, the heater will stop heating, but the water in the heat storage barrel is almost completely unable to be heated, and it is almost impossible to heat the water to the preset water temperature, resulting in the loss of heating work 6 1295723 Even if the heated n scale does not completely cover the heater, when the attached scale has accumulated the thickness of the phase #, the currently known ground cannot be automatically measured at all. In the case of the use of the benefits, ^ 7 benefits = the internal heater, so the heater is getting worse and worse, the user can not know, and then exhausted. Of course, there is also a waste of power in the package. At present, there is also a change in the temperature of the heater when the heater is measured. In order to control the occurrence of the air-burning phenomenon, the temperature is changed to two: = "There is a point of existence, that is, when the heater is applied to the Tuas, '豕, the temperature is still low and the temperature is heated, but if the storage is under the condition, the heater changes from low temperature to high temperature, then high temperature. = The critical upper limit temperature of the hot water (ie the temperature at which it is burned), the second heater can be reached in a period of time, but if the air consumption of the air is generated, it is detected without waiting for the heater. The temperature ^ can be used as early as possible, so it is easy to delay, causing the degree of heating to stop. 'The heater does not have:: The electric raft is damaged. But it may have another 'if the heater surface is attached When the scale is thick, the heating efficiency will gradually deteriorate, but if it is judged by the temperature change caused by the shell to the phase heat, because: =: in the heater order, the temperature root is too inconsistent. The heating process of sucking the crane is also impossible. Knowing that the upper limit temperature of the force is 1^, so [the content of the invention; whether the heating has been covered by the scale of the scale. 7 1295723 The edge is that in order to improve the surface area of the heater, the temperature sensor is not correct. The invention detects the effect of heating, and immediately detects the power failure before the air-burning occurs earlier. The present invention is a method of detecting current, and the current change occurring when the heater actually performs heating, Compared with the current change in the normal heating state, it is used as a basis for judging whether the heater is heated or not. Therefore, by the above method, the heater performs the normal heating process under normal conditions, but if The current after heating is compared with the normal current change, and when it occurs outside the error range, the heater stops heating and provides an indication of the abnormal state to warn the user and increase the safety of the use of the electric water heater. The way to detect the change of current is not only fast and accurate, but also can be used not only when the temperature after the heater is heated has risen to a certain level. When the power is cut off at the same time to protect the heater, in order to prevent the heater from being damaged due to high temperature. Secondly, when the above-mentioned detection current changes, when the surface of the heater is attached with scale and is heavily covered, there is no immediate danger. Occurs, can still be known by the change of the current consumption of the heater, to remind the user of the attention and replacement, thereby maintaining the optimal performance of the electric water heater and avoiding unnecessary waste of power. Therefore, the present invention can be The following embodiments, together with the accompanying drawings, are fully understood and implemented: [Embodiment] Please refer to the second figure, the present invention is provided with a current on the control circuit of the heater 8 1295723 of the electric water heater. The detector or the detecting circuit enables the detection of the change of the current generated by the heater when it is heated, and thereby provides the basis for determining whether the heater is heated or not by the data of the current change. The control method of the invention is as follows: 1. First, after the power of the electric water heater is turned on, the temperature in the heat storage barrel is detected. 2. If the temperature in the heat storage tank is higher than the preset low temperature value, the heater will perform a normal heating procedure. 3. However, if the temperature in the heat storage tank does not reach or falls below the preset low temperature value, the heater will be heated and the heater will be stopped after a certain period of time. 4. Then, the current change that occurs during the actual heating of the heater is detected by the current sensor or circuit, and then compared with the current change in the normal heating state, if it is within a predetermined error range, That is, the condition that the heat storage tank is filled with water without heating abnormality causes the heater to perform a normal normal heating process. 5. However, if the current change occurring during the actual heating of the heater in the third step is compared with the current change in the normal heating state, if it is outside the predetermined error range, it indicates that the air may be burned or the surface of the heater may be scaled. Too thick, causing an abnormality in heating, which in turn causes the heater to stop heating, and at the same time emits an abnormal signal (which can be a light, a display or a sound) to alert or warn the user. Therefore, through the above-mentioned weeks, the continuous detection and comparison, even when the surface of the heater is attached with severe scale, although there is no immediate danger, it will be known from the change of the current consumption of the heater. In addition, it is possible to detect whether the heating condition is abnormal at any time, and promptly remind the user to perform inspection or maintenance to maintain the optimal heating performance of the electric water heater and avoid unnecessary waste of unnecessary power. At the same time, in order to detect the change of current, not only the reaction speed is fast and accurate, but also when the temperature after the heater is heated has not risen to a certain extent, it can be known by the change of the current consumption, and then immediately Turn off the power to protect the heater to prevent the heater from being damaged due to high temperature, improve the safety of the electric water heater, and prevent the electric water heater from being seriously burnt. The above description of the preferred embodiments of the present invention has been disclosed and described in detail in the embodiments of the present invention. It is out of the spirit and scope of the invention. [Simple description of the drawing] The first figure is a schematic flow chart of the heating control method of the conventional electric water heater. The second figure is a schematic flow chart of a method for preventing air burning of the electric water heater of the present invention. [Main component symbol description] 10