Refrigeration and dehumidification control circuit for fan

Abstract

The utility model relates to a kind of refrigeration and dehumidification control circuit for fan, including compressor starting circuit, fan starting circuit, fan control circuit, compressor control circuit, starting control circuit that are parallelly connected in three-phase power supply L, N phase;Starting control circuit is selected after the series connection of selection switch, compressor heat relay normally closed switch, and it is divided into two ways, one way is in series connection high-voltage switch, low-voltage switch, temperature control switch normally open switch and time-delay switch-on relay, another way is in series connection time-delay switch-off relay normally open switch and fan power relay;Compressor control circuit is in series connection this time-delay switch-on relay normally open switch and compressor ac contactor, and fan control circuit is equipped with time-delay switch-off relay.The circuit can accurate temperature and humidity control and prevent shaking, integrated triple fault protection, with visual monitoring and fan, compressor timing coordination function, improve dehumidification reliability and operation efficiency.

Description

Technical Field

[0001] This utility model relates to a fan circuit, specifically a cooling and dehumidification control circuit for a fan. Background Technology

[0002] With the rapid development of the global wind power industry, especially the continuous expansion of the installed capacity and application scenarios of offshore wind turbines, the internal temperature and humidity environment of the wind turbine nacelle, as the installation carrier of core electrical components, directly affects the operational stability of the equipment. Excessive internal temperature can lead to decreased insulation performance and reduced lifespan of electrical components; excessive humidity can cause condensation, resulting in short circuits and other malfunctions. Therefore, refrigeration and dehumidification equipment has become a key component of the wind turbine nacelle, and the reliability, accuracy, and adaptability of its control circuitry directly determine the dehumidification effect and maintenance costs.

[0003] Current compressor refrigeration and dehumidification control schemes commonly used in wind turbine nacelles still have the following problems: low temperature and humidity control accuracy, unreasonable start-stop logic, and existing control circuits often lack precise temperature and humidity triggering elements. When the temperature control switch contacts experience brief switching due to environmental fluctuations, it can easily cause frequent compressor start-stops, exacerbating compressor wear and shortening equipment lifespan. Inadequate protection mechanisms lead to high equipment failure rates. As the core component of refrigeration and dehumidification, the compressor needs to cope with risks such as overload, high pressure (excessive system pressure), and low pressure (refrigerant leakage). However, existing schemes often lack a complete protection chain: some only have overload protection, without considering high and low pressure faults; some have protection elements, but they are not deeply integrated with the control loop, failing to quickly cut off the circuit when a fault occurs, leading to compressor damage due to continuous abnormal operation; furthermore, the timing coordination between the fan and compressor is lacking. For example, if the fan does not start in advance or does not disconnect after shutdown, it can easily lead to insufficient compressor heat dissipation, further increasing the probability of failure. Summary of the Invention

[0004] This invention addresses the aforementioned technical deficiencies that lead to insufficient reliability, inconvenient maintenance, and high energy consumption in existing refrigeration and dehumidification control circuits, thus hindering the stability of environmental control in wind turbine nacelles and increasing operational risks and maintenance costs for wind turbine units. It provides a wind power refrigeration and dehumidification control circuit with precise temperature and humidity control, comprehensive protection, visual monitoring, and high adaptability.

[0005] The technical solution adopted by this utility model is: a cooling and dehumidification control circuit for a fan, including a compressor starting circuit, a fan starting circuit, a fan control circuit, and a compressor control circuit, all connected in parallel to the L and N phases of a three-phase power supply. The feature is that it further includes a starting control circuit, which is connected in series with a selector switch and a normally closed switch of a compressor thermal relay, then splits into two paths. One path consists of a compressor high-pressure switch, a compressor low-pressure switch, a normally open switch of a temperature control switch, and a compressor delay-on relay connected in series. The other path consists of a fan delay-off relay normally open switch and a fan power relay connected in series. The compressor control circuit consists of a compressor delay-on relay normally open switch and a compressor AC contactor connected in series. The fan control circuit is equipped with a fan delay-off relay. The compressor starting circuit is connected to the compressor via the normally open contact of the compressor AC contactor and the compressor thermal relay connected in series. The fan starting circuit is connected to the fan via the normally open switch of the fan power relay.

[0006] It also includes an input power indicator circuit connected in parallel to the L and N phases of the three-phase power supply, and an input power indicator light is provided on the input power indicator circuit.

[0007] It also includes a compressor operation indicator circuit connected in parallel to the L and N phases of the three-phase power supply. The compressor operation indicator circuit is connected in series with the normally open switch of the compressor AC contactor and the operation indicator light.

[0008] The normally open temperature control switch is connected to a temperature control switch located inside the wind turbine nacelle.

[0009] The beneficial effects of this utility model are: 1. Precise temperature and humidity control to avoid frequent compressor start-stop. The temperature control switch is directly installed in the wind turbine nacelle, which monitors the actual temperature and humidity in the nacelle in real time. The high triggering accuracy solves the problem of untimely or excessive dehumidification caused by detection deviation. The delay anti-shake function of the compressor delay relay effectively filters the brief switching of the temperature control switch caused by environmental fluctuations, avoids frequent compressor start-stop, reduces mechanical wear, and extends equipment life.

[0010] 2. Triple fault protection significantly reduces equipment failure rate: It integrates a triple protection mechanism of compressor thermal relay overload protection, system high pressure protection, and system low pressure protection. All protection components are connected in series in the compressor delay-on relay coil circuit. In case of fault, the compressor control link can be quickly cut off to avoid compressor damage due to continuous abnormal operation. This solves the problems of incomplete protection and slow fault response in existing solutions.

[0011] 3. Visualized status monitoring improves operation and maintenance efficiency: The input power indicator and compressor operation indicator are set to reflect the power supply status and compressor operation status respectively. Operation and maintenance personnel do not need to use professional instruments. They can quickly determine whether the power supply is normal and whether the compressor is running by looking at the indicator lights, thus shortening the troubleshooting time.

[0012] 4. Fan and compressor timing coordination to protect compressor safety: The fan disconnects after shutdown via a time-delayed disconnect relay, ensuring that the compressor continues to dissipate heat after shutdown and preventing damage to the compressor due to residual heat accumulation; at the same time, the fan and compressor start synchronously, ensuring sufficient heat dissipation during compressor operation and solving the problem of insufficient compressor heat dissipation caused by the disordered timing of existing solutions. Attached Figure Description

[0013] Figure 1 This is the circuit diagram of this utility model.

[0014] In the diagram: Three-phase power supply 1, input power indicator HL1, compressor AC contactor KM, compressor AC contactor normally open contact KM-1, compressor AC contactor normally open switch KM-2, compressor thermal relay FR, compressor thermal relay normally closed switch FR-1, fan power relay KA1, fan power relay normally open switch KA1-1, fan time-delay disconnect relay KT2, fan time-delay disconnect relay normally open switch KT2-1, compressor time-delay connection relay KT1, compressor time-delay connection relay normally open switch KT1-1, compressor running indicator HL2, selector switch SA, high-pressure switch HP, low-pressure switch LP, temperature control switch normally open switch ST1, compressor M1, fan M2. Detailed Implementation

[0015] The following explanation, in conjunction with the accompanying drawings, will provide further details.

[0016] Figure 1As shown, a cooling and dehumidification control circuit for a fan includes a compressor starting circuit, a fan starting circuit, a fan control circuit, a compressor control circuit, a start control circuit, an input power indicator circuit, and a compressor operation indicator circuit, all connected in parallel to the three-phase power supply 1L and N phases. The starting control circuit is connected in series with the selector switch SA and the normally closed switch FR-1 of the compressor thermal relay FR, then splits into two paths. One path consists of the compressor high-pressure switch HP, the compressor low-pressure switch LP, the normally open switch ST1 of the temperature control switch, and the compressor time-delay relay KT1 connected in series. The other path consists of the normally open switch KT2-1 of the fan time-delay relay KT2 connected in series and the fan power relay KA1 connected in series. The compressor control circuit consists of the normally open switch KT1-1 of the compressor time-delay relay KT1 connected in series and the compressor AC contactor KM. The fan control circuit includes the fan time-delay relay KT2. The compressor starting circuit connects to the compressor M1 via the normally open contact KM-1 of the compressor AC contactor KM connected in series and the compressor thermal relay FR. The fan starting circuit connects to the fan M2 via the normally open switch KA1-1 of the fan power relay KA1. The input power indicator circuit includes the input power indicator light HL1. The compressor running indicator circuit connects to the normally open switch KM-2 of the compressor AC contactor KM connected in series. And the compressor operation indicator light HL2.

[0017] The temperature control switch ST1 of this utility model is connected to a temperature control switch installed inside the wind turbine nacelle.

[0018] When the temperature and humidity inside the wind turbine nacelle reach the cooling and dehumidification threshold, the selector switch closes, and the temperature control switch located inside the nacelle controls its normally open switch to close. This, together with the compressor high-pressure switch, compressor low-pressure switch, and compressor thermal relay normally closed switch connected in series, forms a circuit to power the compressor delay-on relay coil. After the compressor delay-on relay coil is energized, the compressor delay-on relay normally open switch remains open for a delayed period to avoid vibrations caused by brief on / off cycles due to environmental fluctuations. After the delay ends, the normally open switch closes to power the compressor AC contactor coil. Upon energization, the normally open contacts of the compressor AC contactor close, the compressor starting circuit is activated, and the compressor begins to run. If the compressor thermal relay is overloaded, or if the system is under high or low pressure, the compressor delayed-on relay coil circuit will be immediately disconnected, the normally open contact of the compressor AC contactor will open, and the compressor will stop in an emergency, thus achieving triple fault protection.

[0019] The normally open contact of the fan delay disconnect relay remains closed after the system is powered on, supplying power to the fan power relay coil. When the fan power relay coil is energized, the normally open switch of the fan power relay closes, the fan starting circuit is activated, and the fan starts synchronously to cool the compressor. When the selector switch is open, the fan delay disconnect relay triggers the delay disconnect function, the normally open switch of the fan delay disconnect relay opens with a delay, the fan power relay coil remains energized for a period of time, and the fan continues to run, ensuring that there is still heat dissipation after the compressor stops, avoiding damage to the compressor due to residual heat, and realizing the timing protection of delayed fan shutdown.

Claims

1. A cooling and dehumidification control circuit for a fan, comprising a compressor starting circuit, a fan starting circuit, a fan control circuit, and a compressor control circuit, all connected in parallel to the L and N phases of a three-phase power supply, characterized in that: It also includes a start-up control circuit, which is connected in series with a selector switch and a normally closed switch of the compressor thermal relay, and then splits into two paths. One path is connected in series with a compressor high-pressure switch, a compressor low-pressure switch, a normally open switch of the temperature control switch, and a compressor time-delay relay. The other path is connected in series with a fan time-delay relay normally open switch and a fan power relay. The compressor control circuit is connected in series with a compressor time-delay relay normally open switch and a compressor AC contactor. The fan control circuit is equipped with a fan time-delay relay. The compressor start-up circuit is connected to the compressor in series with the compressor AC contactor normally open contact and the compressor thermal relay. The fan start-up circuit is connected to the fan in series with the fan power relay normally open switch.

2. The refrigeration and dehumidification control circuit for a fan according to claim 1, characterized in that: It also includes an input power indicator circuit connected in parallel to the L and N phases of the three-phase power supply, and an input power indicator light is provided on the input power indicator circuit.

3. The refrigeration and dehumidification control circuit for a fan according to claim 1, characterized in that: It also includes a compressor operation indicator circuit connected in parallel to the L and N phases of the three-phase power supply. The compressor operation indicator circuit is connected in series with the normally open switch of the compressor AC contactor and the operation indicator light.

4. The refrigeration and dehumidification control circuit for a fan according to claim 1, characterized in that: The normally open temperature control switch is connected to a temperature control switch located inside the wind turbine nacelle.

Images