Circulating water winter energy-saving and constant-temperature automatic control unit

Abstract

The invention discloses a circulating water winter energy-saving and constant-temperature automatic control unit which comprises a temperature controller, a fan automatic control primary loop, a fan automatic control secondary loop and a temperature sensing probe, and the temperature sensing probe is electrically connected to the temperature controller. The fan manual start-stop primary loop comprises a first manual operation loop air switch, a first contactor, a first thermal protection relay and a cooling tower fan motor which are sequentially connected. The fan manual start-stop secondary loop comprises a U21 which is sequentially connected with an FR, a second stop button switch, a first start button switch and a self-protection loop contactor normally open contact KM1. According to the invention, low temperature and cold wind in winter, return water heat and control of the temperature controller are ingeniously utilized, so that the temperature of circulating water is in a set dynamic balance, energy consumption is reduced, the hydraulic oil temperature of the injection molding machine is improved, the viscosity of the hydraulic oil is reduced, the fluidity of the hydraulic oil is improved, and equipment is in a more excellent operation state.

Description

Technical Field

[0001] This invention relates to the field of automated control technology for circulating water temperature control, specifically to an automated control unit for energy saving and temperature control of circulating water in winter. Background Technology

[0002] During our daily production process in the workshop, we observed that the equipment and molds do not require several degrees of circulating water for cooling in winter, and excessively low circulating water temperature is actually not conducive to production.

[0003] Firstly, injection molding machines are a type of hydraulic equipment, which relies on hydraulic oil to transmit power and achieve its working purpose. During operation, the hydraulic oil and circulating water exchange heat in the oil cooler. The circulating water carries away heat from the hydraulic oil, preventing it from overheating. In winter, observations show that the circulating water temperature is typically below 10℃. Our monitoring data for the workshop's circulating water system shows that at an air temperature of 8℃, the circulating water temperature is 9.5℃, and at 5℃, it is 6.5℃. The lower the air temperature, the lower the circulating water temperature. The ideal operating temperature for hydraulic oil is around 45℃. In winter, the excessively low circulating water temperature causes a significant amount of heat to be carried away from the hydraulic oil by the oil cooler, making the hydraulic oil more viscous. Higher viscosity hydraulic oil has poorer fluidity, greater resistance, increased pump noise, and increased energy consumption, thus depriving the machine of its optimal operating condition.

[0004] Secondly, if the external water supply to the mold is a circulating water system, excessively low water temperature will cause the mold temperature to be too low, resulting in poor melt flow, leading to unsatisfactory products, decreased gloss, and increased defective products such as obvious weld lines.

[0005] Finally, during winter production, the cooling tower fans of the circulating water system run 24 hours a day, while the equipment and molds in the workshop do not require such low water temperatures. In fact, there is an idle consumption of electricity and fans, which is a waste.

[0006] Therefore, when the temperature is 10℃ or below, the workshop needs to appropriately increase the circulating water temperature to ensure high-efficiency and high-quality production! Thus, from a scientific, automated, practical, and innovative perspective, developing a "circulating water winter energy-saving and constant temperature automated control unit" is of positive significance to the company's production! Summary of the Invention

[0007] To solve the above technical problems, the technical solution provided by the present invention is: an automatic control unit for energy saving and constant temperature of circulating water in winter, including a temperature controller, a primary circuit for automatic control of the fan, a secondary circuit for automatic control of the fan, and a temperature sensor, wherein the temperature sensor is electrically connected to the temperature controller and its other end is installed in the water tank;

[0008] The automatic control unit for the fan consists of a primary circuit for automatic fan control and a secondary circuit for automatic fan control.

[0009] The automatic control primary circuit of the fan includes an automatic air switch QF2, a contactor KM2, a thermal protection relay, and a cooling tower fan motor connected in sequence.

[0010] The automatic control secondary circuit of the fan consists of a temperature controller, a temperature sensor, an intermediate relay, indicator lights, and a fuse.

[0011] Furthermore, the cooling tower fan operation indicator lights are installed on the automatic start / stop secondary circuit of the fan, and there are three sets of cooling tower fan operation indicator lights. The lights illuminate when the fan is running and turn off when the fan stops. The three sets of cooling tower fan operation indicator lights are E1, E2, and E3.

[0012] Furthermore, the temperature controller is equipped with a water temperature indicator light and an intermediate relay.

[0013] The advantages of the invention compared to existing technologies are:

[0014] 1. This invention utilizes the aforementioned electrical components and circuit principles to achieve automated start-stop control of the circulating water cooling tower fan. In cold winters, it effectively increases and stabilizes the circulating water temperature, avoids wasted cooling tower fan energy, saves electricity, reduces enterprise expenses, and lowers production costs.

[0015] 2. This automated control unit significantly increases the hydraulic oil temperature of hydraulic equipment (such as injection molding machines) during winter, reduces hydraulic oil viscosity, and improves hydraulic oil flowability, allowing the equipment to operate in a better state. Simultaneously, molds connected to external circulating water will not experience excessively low mold temperatures, reducing product defect rates, improving the quality of injection molded parts and production efficiency, and better ensuring the smooth operation of the enterprise's production.

[0016] 3. This invention avoids the waste of cooling tower fans in winter and significantly extends the service life of the fans and fan belts. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an automated control unit for energy saving and constant temperature of circulating water in winter according to the present invention.

[0018] As shown in the figure: QF1, manual operation circuit air switch; KM1, manual operation circuit contactor; FR, thermal protection relay; M, cooling tower fan motor; QF2, automatic control unit air switch; KM2, automatic control unit contactor; FU1-2, fuse; KA1-KA4, intermediate relay; E1-E3, cooling tower fan working indicator light; E4, water temperature indicator light.

[0019] Among them, FR and M are the shared parts of the original manual primary circuit and the newly invented automatic control primary circuit. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings.

[0021] The present invention will be described in detail with reference to the accompanying drawings.

[0022] In a specific implementation, the present invention provides an automated control unit for energy saving and constant temperature of circulating water in winter, including a temperature controller, a primary circuit for automatic fan control, a secondary circuit for automatic fan control, and a temperature sensor. The temperature sensor is electrically connected to the temperature controller, and its other end is installed in the water tank.

[0023] The automatic control unit for the fan consists of a primary circuit for automatic fan control and a secondary circuit for automatic fan control.

[0024] The automatic control primary circuit of the fan includes an automatic air switch QF2, a contactor KM2, a thermal protection relay, and a cooling tower fan motor M connected in sequence; the thermal protection relay FR and the cooling tower fan motor M are shared by the manual control primary circuit and the automatic control primary circuit of the fan.

[0025] The automatic control secondary circuit for the fan consists of a temperature controller, a temperature sensor, intermediate relays, indicator lights, and fuses. The aforementioned automated control unit uses the start-stop control of the circulating water cooling tower fan as its entry point. A temperature controller is connected to the fan automatic control secondary circuit. Whether the temperature controller is energized depends on whether the circulating water pumps in the workshop are running. When any one of the circulating water pumps (No. 1, No. 2, or No. 3) is started, the corresponding intermediate relay coil (KA1, KA2, or KA3) is energized, the normally open contact of the corresponding intermediate relay is closed, the temperature controller is energized, and the circulating water temperature monitoring and control circuit enters automatic operation.

[0026] This circuit uses a temperature controller to set the water temperature. A temperature sensor transmits the circulating water temperature data, and the temperature controller then connects or disconnects the coil voltage of intermediate relay KA4 or the operating voltage of the water temperature indicator light E4 based on this data. The other automatic control secondary circuit starts from phase B at the lower end of QF2, and sequentially includes fuse FU1, the normally closed thermal protection FR contact, the normally open intermediate relay KA4 contact, the normally closed KM1 contact (interlocked with the manual circuit contactor), and the coil of the automatic control circuit contactor KM2. This circuit uses the connection or reset of the normally open KA4 contact to control the engagement or disengagement of the KM2 main contacts, thus achieving automatic start and stop of the cooling tower fan.

[0027] The automatic control secondary circuit for the fan consists of two lines, each playing a different role:

[0028] The first automatic control secondary circuit draws power from phase C at the lower end of QF2. It includes, in sequence, fuse FU2, normally open contacts of parallel intermediate relays KA1, KA2, and KA3, a temperature controller, the coil of intermediate relay KA4 connected to point 2 of the temperature controller, a water temperature indicator light E4 connected to point 3 of the temperature controller, 220V power supplies to the temperature controller at points 4 and 5, and a temperature sensor connected to points 11 and 12 of the temperature controller, which is installed inside the circulating water tank. The function of this automatic control secondary circuit is to set the circulating water temperature, monitor the circulating water temperature, and send an on / off operating voltage to the coil of intermediate relay KA4. The second automatic control secondary circuit draws power from phase B at the lower end of QF2. It includes, in sequence, fuse FU1, normally closed contact of thermal protection FR, normally open contact of intermediate relay KA4, normally closed contact of KM1, and the coil of contactor KM2. The function of this automatic control circuit is to execute the action commands of the temperature controller, and control the contactor KM2 to engage or disengage by opening or resetting the normally open contact KA4, thereby realizing the automatic start and stop of the cooling tower fan.

[0029] As a further explanation of the present invention, the cooling tower fan operation indicator lights E1-E3 are provided on the automatic start-stop secondary circuit of the fan, and there are three sets of cooling tower fan operation indicator lights.

[0030] As a further explanation of the present invention, the temperature controller is equipped with a water temperature indicator light E4 and an intermediate relay KA4.

[0031] As a further explanation of the invention, it also includes intermediate relays KA1, KA2, and KA3, which are used to energize the lower ends of multiple water pump contactors. The coil power supply of intermediate relays KA1, KA2, and KA3 comes from the lower ends of the contactors of circulating water pumps No. 1, No. 2, and No. 3, respectively. When the automatic circulating water control unit is needed, the manual primary circuit breaker QF1 is disconnected, the automatic control primary circuit breaker QF2 is closed, and any circulating water pump is started. The coil of the corresponding intermediate relay KA1, KA2, or KA3 will be energized, the normally open contact of the corresponding intermediate relay will close, and the temperature controller will be energized (terminals 4 and 5 on the temperature controller are the 220V power supply for the temperature controller), entering the automatic water temperature monitoring and control state. When production ends, the circulating water pump is turned off, and the temperature controller is de-energized to prevent the fan from being accidentally started after production stops. The workshop can switch between manual and automatic control at will according to production needs, making it very convenient to use.

[0032] As a further explanation of the present invention, the lower B phase of the automatic control unit air switch QF2 to the neutral line N is another fan automatic control secondary circuit. The normally closed contact of the manual operation circuit contactor KM1 is connected in series in the fan automatic control secondary circuit, and the normally closed contact of the automatic control circuit KM2 is connected in series in the manual operation circuit U21 to the neutral line N as an interlock.

[0033] Example:

[0034] The temperature controller is powered from phase C of QF2, passing through fuse FU2, and sequentially through the normally open contacts of the parallel intermediate relays KA1, KA2, and KA3 to terminals "1" and "5" of the temperature controller. Terminal "4" of the temperature controller is used to connect to the neutral wire N. Terminals 4 and 5 are the 220V power supply for the temperature controller. Terminals 1, 2, and 3 of the temperature controller form a set of normally open and normally closed contacts. Terminals "13" and "14" of the coils of intermediate relays KA1, KA2, and KA3 are connected to the neutral wire N at one end, and the other end is connected to phase B of the contactors of circulating water pumps #1, #2, and #3, respectively. When any circulating water pump is started, the corresponding intermediate relay coil is energized, the normally open contact closes, the temperature controller is powered on and begins to work, and the automation control unit enters the working state. When the workshop stops production, the circulating water pumps are shut down, the temperature controller is de-energized, and the automation control unit enters the shutdown state.

[0035] When using the automatic control unit in winter, the temperature controller is set to 17℃, and the water temperature in the tank will remain constant between 17℃ and 19℃. When the water temperature in the tank reaches 19℃, the temperature controller's "2" terminal will output 220V, energizing the coil of intermediate relay KA4. The normally open contact of intermediate relay KA4 closes, connecting the secondary circuit of contactor KM2 in the automatic control unit. The coil of contactor KM2 in the automatic control unit is energized, its main contacts close, and the cooling tower fan runs to compensate for cooling. At the same time, the cooling tower fan operation indicator lights E1-E3 illuminate.

[0036] When the temperature inside the circulating water tank drops to 17℃, the temperature sensor transmits the detected temperature data, the temperature controller's "2" terminal stops outputting, the intermediate relay KA4 is de-energized, the normally open contact of the intermediate relay KA4 resets, the main contact of the automatic control unit contactor KM2 opens, the cooling tower operating indicator lights E1-E3 go out, and the cooling tower fan stops. Simultaneously, the temperature controller's "3" terminal outputs 220V, the water temperature indicator light E4 illuminates, and the circulating water enters a natural cooling state. The temperature controller's terminals 11 and 12 are connected to the temperature sensor, with terminal 11 being the "positive" and terminal 12 the "negative." The temperature sensor is installed inside the circulating water tank. The temperature controller and temperature sensor are crucial components of this automated control unit, monitoring and controlling the circulating water temperature and issuing action commands. The normally open terminal of the temperature controller is also connected to the coil of the intermediate relay KA4. When the water temperature inside the circulating water tank reaches the temperature controller's set value, the KA4 coil is de-energized, the normally open contact of KA4 resets, and the fan stops. When the water temperature in the circulating water tank is 2 degrees higher than the set value, the KA4 coil is energized, the normally open contact of KA4 is closed, KM2 is attracted, and the cooling tower fan starts running.

[0037] This automatic control unit achieves a dynamic balance of circulating water temperature between cold winter winds and low temperatures, circulating water return heat, and fan compensation, thus achieving the goals of energy saving and constant temperature!

[0038] The circulating water system consists of a cooling tower and fan, water tank, water pump, inlet and outlet water pipes, and electrical control cabinet. The water pump delivers water from the tank into the workshop, where it undergoes heat exchange on the equipment and molds before flowing back to the top of the cooling tower. As the return water flows down from the top of the cooling tower, it is evenly dispersed by the packing material inside the tower. The fan at the top of the cooling tower rotates, driving the airflow to cool the flowing return water, which then flows back to the water tank, creating a continuous cycle.

[0039] The present invention has the following advantages:

[0040] 1. By adopting the above-mentioned electrical components and control circuits, energy-saving and constant temperature automatic control of circulating water temperature is achieved, saving national electricity, reducing enterprise expenses and lowering enterprise production costs.

[0041] This invention fully utilizes the low temperatures and cold winds of winter to cool the circulating water return. The cooling tower fan is used for compensating for the cooling effect, with a low start-up frequency and short operating time. During the trial, the hydraulic equipment used were injection molding machines, ranging from 1000T to 2200T, all of which are large-scale equipment. Relevant usage data are as follows:

[0042]

[0043] The cooling tower fan has a power of 7.5KW. Assuming 28 production days per month, and an average electricity cost of 0.7 yuan / kWh across peak, off-peak, and valley periods, if the circulating water cooling tower fan is manually controlled, it will operate 24 hours a day. If it is automatically controlled, conservatively assuming 1 / 5 of the operating time per day, and considering winter usage in some regions for two months:

[0044]

[0045] It can save 5644.80 yuan in two months. The longer the winter and the lower the temperature in the region, the more electricity it saves and the more practical it is.

[0046] 2. It solved the problem of excessively low circulating water temperature (<10℃) in winter, achieving the goal of constant temperature.

[0047] The comparison is as follows:

[0048]

[0049] As can be seen from the table, the energy-saving constant temperature automatic control unit greatly improves the hydraulic oil temperature of the injection molding machine, reduces the hydraulic oil viscosity, and improves the hydraulic oil fluidity, so that the equipment is in a better operating state. At the same time, the mold with external circulating water will not have the problem of low mold temperature, reducing the product defect rate, improving production efficiency, and ensuring smooth production.

[0050] 3. It effectively avoids the empty consumption of cooling tower fans and significantly extends the service life of fans and fan belts.

[0051] Previously, three B-2000 V-belts were replaced annually; now, they are replaced every 1.5 to 2 years. Although V-belts are not expensive, they reduce maintenance frequency and save on operating costs. They also reduce wear on the fan bearings, extending the fan's lifespan.

[0052] This invention cleverly utilizes the cold winds and low temperatures of winter, along with the heat brought back by the circulating water return (no additional heating required), and the monitoring and control by the temperature controller and temperature probe, to achieve energy saving and constant temperature during the use of circulating water.

[0053] Additionally, it should be noted that the circuit diagram includes two parts: a manual control circuit for the fan, comprising a primary manual circuit (circuit breaker QF1--KM1--FR-M) and a secondary manual circuit (U21 to neutral line N). The manual control circuit is the control method commonly used by various enterprises and is not within the scope of this invention. Both are shown simultaneously for two reasons: firstly, they are connected in the circuit; secondly, they demonstrate compatibility and non-conflict, allowing enterprises to switch between them arbitrarily according to production needs. The automatic control circuit unit for the fan in the circuit diagram is the subject of this invention.

[0054] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A circulating water winter energy saving and constant temperature automatic control unit, characterized in that, It includes a temperature controller, a primary circuit for automatic fan control, a secondary circuit for automatic fan control, and a temperature sensor. The temperature sensor is electrically connected to the temperature controller, and its other end is installed inside the water tank. The automatic control unit for the fan consists of a primary circuit for automatic fan control and a secondary circuit for automatic fan control. The automatic control primary circuit of the fan includes an automatic air switch QF2, a contactor KM2, a thermal protection relay, and a cooling tower fan motor connected in sequence. The automatic control secondary circuit of the fan consists of a temperature controller, a temperature sensor, an intermediate relay, indicator lights, and a fuse.

2. The automated control unit for energy saving and constant temperature of circulating water in winter according to claim 1, characterized in that: The cooling tower fan operation indicator light is installed on the automatic start / stop secondary circuit of the fan, and there are three sets of cooling tower fan operation indicator lights.

3. The automated control unit for energy saving and constant temperature of circulating water in winter according to claim 1, characterized in that: The temperature controller is equipped with a water temperature indicator light and an intermediate relay.

4. The circulating water winter energy saving and constant temperature automatic control unit according to claim 1, characterized in that: It also includes intermediate relay one, intermediate relay two and intermediate relay three, which are used to connect to the lower end of multiple water pump contactors.

5. The winter energy saving and constant temperature automatic control unit for circulating water according to claim 1, characterized in that: The lower B phase to neutral line of the air switch QF2 of the automatic control unit is the secondary circuit of the automatic control of the fan. The normally closed contact KM1 of the manual operation circuit contactor is connected in series in the secondary circuit of the automatic control of the fan as an interlock.

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