Thermal control system in dome cover of large-aperture telescope

Abstract

The invention relates to the technical field of special engineering environment control, and discloses a large-aperture telescope dome cover internal thermal control system, which comprises a dome air conditioner thermal control system and a dome emergency exhaust system, and is characterized in that the dome air conditioner thermal control system has variable-temperature cooling and preset low-environment-temperature cooling functions; the thermal environment adjusting module is used for adjusting the thermal environment in the dome cover based on preset thermal control requirements; the dome emergency exhaust system is used for conducting rapid cooling adjustment when the adjusting effect of the dome air conditioner thermal control system cannot meet the preset thermal control requirement. According to the dome air conditioner thermal control system, the cooling mode can be flexibly adjusted according to different environment temperatures and observation requirements, the dome emergency exhaust system serves as a standby scheme, and when the air conditioner thermal control system cannot meet the thermal control requirement, rapid starting and rapid cooling adjustment can be conducted. The emergency mechanism ensures that the telescope can still quickly reach the preset working temperature under extreme weather or emergency conditions, and is beneficial to improving the observation benefit of the telescope.

Description

Technical Field

[0001] The present invention relates to the technical field of special engineering environment control, and particularly to a thermal control system inside the dome of a large-aperture telescope. Background Art

[0002] The scientific objectives of optical telescopes (such as observing distant celestial bodies and capturing clear images) require high-precision pointing and high imaging quality. The components of large-aperture telescopes have a large thermal inertia, that is, a strong ability to resist temperature changes, and it is difficult to quickly adapt to environmental temperature changes, resulting in a temperature difference between the components and the surrounding environment. The larger the telescope aperture, the greater the thermal inertia of its components (such as the mirror surface and support structure), resulting in a lag in temperature changes. This lag will cause local seeing problems, leading to imaging distortion (image plane movement and distortion), and affecting imaging accuracy. When the site, hardware performance, and instrumentation of the telescope are fixed, improving local seeing and optimizing the observation strategy become the key to improving imaging quality.

[0003] In order to reduce the impact of temperature difference on imaging quality, it is necessary to adopt thermal control technology to control the temperature difference inside and outside the telescope dome. Different from the almost constant indoor set temperature of a conventional air-conditioning system, the dome thermal control system needs to adjust its set temperature according to the predicted outdoor ambient temperature at the moment when the telescope dome is opened every day, which poses extremely high requirements for the adjustment ability and environmental adaptability of the thermal control system. In related technologies, generally, reasonable air flow organization is used to alleviate the impact of local seeing. However, since the outdoor temperature varies greatly throughout the year, a thermal control system with full-time adjustment ability and environmental adaptability is required inside the dome to meet the annual cooling demand of the large-aperture telescope dome, significantly reduce the telescope's observation preparation time, and improve its scientific benefits. Summary of the Invention

[0004] In view of this, the present invention provides a thermal control system inside the dome of a large-aperture telescope to solve the problem of how to ensure the full-time guarantee of the thermal environment inside the dome of a large-aperture telescope.

[0005] The present invention provides a thermal control system inside the dome of a large-aperture telescope, including a dome air-conditioning thermal control system and a dome emergency exhaust system. Among them, the dome air-conditioning thermal control system has variable-temperature cooling and preset low-environment-temperature cooling functions, and is used to adjust the thermal environment inside the dome based on preset thermal control requirements; the dome emergency exhaust system is used for rapid cooling adjustment when the adjustment effect of the dome air-conditioning thermal control system cannot meet the preset thermal control requirements.

[0006] Beneficial effects: The dome air-conditioning thermal control system has functions of variable-temperature cooling and preset low ambient temperature cooling, and can precisely adjust the temperature environment inside the dome according to the thermal control requirements during the operation of the telescope. It helps to reduce the influence of temperature deviation on the telescope optical system, ensuring the accuracy and stability of observation data. It can flexibly adjust the cooling mode according to different ambient temperatures and observation requirements. The dome emergency exhaust system, as a backup solution, can be quickly started and perform rapid cooling adjustment when the air-conditioning thermal control system fails to meet the thermal control requirements. This emergency mechanism ensures that the telescope can still quickly reach the preset working temperature in extreme weather or emergencies, which helps to improve the observation efficiency of the telescope. A stable thermal environment helps to reduce the influence of structural thermal deformation and local seeing on the telescope optical system, thereby improving the quality and resolution of the observation image.

[0007] In an optional implementation, the dome air-conditioning thermal control system includes a dome air-conditioning terminal system, a stepless variable-temperature cold source system, and a cold source distribution system. Among them, the dome air-conditioning terminal system is arranged in the main mirror room of the telescope and is used to adjust the temperature inside the dome; the stepless variable-temperature cold source system is used to provide a wide-temperature-range variable-temperature refrigerant that meets the annual cooling demand for the dome air-conditioning terminal system; the cold source distribution system is used to connect the stepless variable-temperature cold source system and the dome air-conditioning terminal system to realize the circulation of the refrigerant between the two, including a circulating water pump, a circulating refrigerant, a circulating pipeline and its accessories.

[0008] Beneficial effects: The dome air-conditioning terminal system is directly arranged in the main mirror room of the telescope, can quickly respond to temperature changes, and precisely adjust the thermal environment inside the dome. Through the wide-temperature-range variable-temperature refrigerant provided by the stepless variable-temperature cold source system, the system can flexibly adjust the cooling temperature according to actual needs, avoiding the influence of temperature deviation on the telescope optical system, thereby improving the accuracy of observation data and the image quality. The stepless variable-temperature cold source system can provide a wide-temperature-range refrigerant that meets the annual cooling demand and adapts to the changes of different seasons and ambient temperatures. Whether it is high-temperature summer or low-temperature winter, the system can provide appropriate cooling capacity to ensure that the telescope always operates within the optimal temperature range. The cold source distribution system realizes the efficient circulation of the refrigerant between the stepless variable-temperature cold source system and the dome air-conditioning terminal system through a circulating water pump, a circulating pipeline and its accessories, optimizes the refrigerant delivery efficiency, reduces energy loss, and lowers the operating energy consumption, meeting the requirements of energy conservation and environmental protection. The cold source distribution system uses reliable circulating water pumps, pipelines and accessories to ensure the stability and continuity of the refrigerant circulation.

[0009] In an optional implementation, the dome air-conditioning terminal system includes vertical fan coil units. The vertical fan coil units are placed on the ground of the main mirror room and are evenly arranged in a ring along the outer wall of the main mirror room. They are connected to the stepless variable-temperature cold source system through the cold source distribution system, and both the running units and standby units are configured for the vertical fan coil units.

[0010] Beneficial effects: The vertical fan coil units are arranged annularly and evenly along the outer wall of the main mirror room, which can achieve uniform adjustment of the temperature in the main mirror room, avoid local overheating or overcooling, thereby reducing the thermal deformation of the telescope optical system caused by uneven temperature, and thus improving the observation accuracy. The vertical fan coil units are directly installed on the floor of the main mirror room, close to the heat source, and can quickly absorb and disperse heat to achieve efficient cooling. The operation units and standby units are configured together, and each operation unit is equipped with a standby unit. When a fault occurs or maintenance is required for the operating unit, the standby unit can be immediately put into use to ensure the uninterrupted operation of the system and improve the reliability and stability of the system.

[0011] In an optional embodiment, the stepless variable temperature cold source system includes a wide-temperature-range variable temperature cooling device and a low ambient temperature refrigeration guarantee device. Among them, the wide-temperature-range variable temperature cooling device is arranged in the cold source machine room and consists of multiple stepless variable temperature cold source units connected in parallel for regulating the water supply temperature; the low ambient temperature refrigeration guarantee device is used to ensure the reliable operation of the stepless variable temperature cold source units under low ambient temperature.

[0012] Beneficial effects: The wide-temperature-range variable temperature cooling device consists of multiple stepless variable temperature cold source units connected in parallel, which can provide a wide range of water supply temperature adjustment, enabling the system to adapt to different seasons, different ambient temperatures, and different thermal control requirements of the telescope, and ensuring that the temperature in the dome is always within the optimal range. Through multiple stepless variable temperature cold source units connected in parallel, when one of the units fails, the other units can still continue to operate to ensure uninterrupted cooling of the system. The low ambient temperature refrigeration guarantee device is used to ensure the reliable operation of the stepless variable temperature cold source units under low temperature environment. Through the cooperation of the wide-temperature-range variable temperature cooling device and the low ambient temperature refrigeration guarantee device, the system can achieve stable cooling throughout the year and ensure that the telescope always operates within the optimal temperature range.

[0013] In an optional embodiment, the wide-temperature-range variable temperature cooling device includes a stepless temperature-adjusting normal temperature cold source unit with a water temperature adjustment range of a first temperature range; a stepless temperature-adjusting low temperature cold source unit with a water temperature adjustment range of a second temperature range; a stepless temperature-adjusting ultra-low temperature cold source unit with a water temperature adjustment range of a third temperature range; the temperature in the first temperature range is greater than the temperature in the second temperature range, the temperature in the second temperature range is greater than the temperature in the third temperature range, and each type of unit is configured with an operation unit and a standby unit together.

[0014] Beneficial effects: The equipment covers the cooling demand in a wide temperature range from normal temperature to ultra-low temperature through three types of cold source units, and can flexibly respond to different seasons, different ambient temperatures, and different thermal control requirements of the telescope, ensuring that the temperature inside the dome is always within the optimal range. Each type of cold source unit is configured with an operating unit and a standby unit, that is, each operating unit is equipped with a standby unit, ensuring that when the operating unit fails or needs maintenance, the standby unit can be immediately put into use to ensure uninterrupted cooling of the system, significantly improving the reliability and stability of the system.

[0015] In an alternative embodiment, the low ambient temperature refrigeration guarantee equipment includes a split-type condensation and heat dissipation device, a duty heating device, and an anti-freeze heat exchange medium. Among them, the split-type condensation and heat dissipation device is arranged on the roof of the cold source machine room, and the split-type condensation and heat dissipation device is arranged corresponding to the stepless variable temperature cold source unit one by one. The split-type condensation and heat dissipation device is connected to the stepless variable temperature cold source unit through a cooling water pipeline, and is used to maintain the condensation pressure required for the normal operation of each cold source unit; the duty heating device is evenly arranged along the outer wall of the cold source machine room to ensure that the working environment temperature of the wide temperature range variable temperature cooling equipment is not lower than the preset temperature; the anti-freeze heat exchange medium is arranged in the circulation pipeline to prevent the circulation pipeline from freezing within the system operating temperature range.

[0016] Beneficial effects: The split-type condensation and heat dissipation device is arranged on the roof of the cold source machine room, corresponding to the stepless variable temperature cold source unit one by one, and is connected through a cooling water pipeline. The split-type condensation and heat dissipation device can effectively maintain the condensation pressure, ensuring that the cold source unit can still operate stably in a low temperature environment. The duty heating device is evenly arranged along the outer wall of the cold source machine room, which can ensure that the working environment temperature of the wide temperature range variable temperature cooling equipment is not lower than the preset temperature, avoiding damage to the cold source unit and its auxiliary equipment in a low temperature environment, and extending the service life of the equipment. The anti-freeze heat exchange medium is arranged in the circulation pipeline, which can prevent the liquid in the pipeline from freezing in a low temperature environment, ensuring the fluidity of the cooling water or refrigerant in the circulation pipeline, and avoiding system interruption or equipment damage caused by pipeline freezing. Through the combined action of the split-type condensation and heat dissipation device, the duty heating device, and the anti-freeze heat exchange medium, the system can maintain normal operation in an extremely low temperature environment to ensure uninterrupted cooling throughout the year.

[0017] In an alternative embodiment, when the wide temperature range variable temperature cooling equipment adjusts the water supply temperature, it determines the initial water supply temperature T2 of the stepless variable temperature cold source unit according to the predicted target temperature T1 inside the dome, T2 = T1 - T’, where T’ represents the temperature difference value that meets the cooling demand of the dome air-conditioning terminal system; and dynamically adjusts the water supply temperature according to the temperature difference between the inlet air dew point T3 of the dome air-conditioning terminal system and the initial water supply temperature T2.

[0018] Beneficial effects: Based on the predicted target temperature T1 inside the dome cover, the system determines the initial water supply temperature T2 through the formula T2 = T1 - T', ensuring that the water supply temperature can meet the cooling demand of the dome air-conditioning terminal system, avoiding the problems of insufficient cooling or over-cooling caused by the poor adaptability of the water supply temperature in the traditional cold source system, and significantly improving the thermal control effect. According to the temperature difference between the inlet air dew point T3 and the initial water supply temperature T2 of the dome air-conditioning terminal system, the water supply temperature is dynamically adjusted, enabling the system to respond in real time to the temperature changes inside the dome cover and ensuring that the thermal environment always remains within the optimal range. Dynamically adjusting the water supply temperature enables the thermal control system to effectively adapt to outdoor temperature changes, achieve on-demand cooling and continuous cooling, and improve the stability of the system.

[0019] In an alternative embodiment, dynamically adjusting the water supply temperature includes: when T2 - T3 > T, where T represents the temperature difference threshold, reducing the water supply temperature to T3 + T for rapid cooling with a large temperature difference; when -T ≤ T2 - T3 ≤ T, maintaining the default water supply temperature T2 for micro-frost cooling; when T2 - T3 < -T, maintaining the default water supply temperature T2 for frost cooling.

[0020] Beneficial effects: When T2 - T3 > T, the system achieves rapid cooling with a large temperature difference by reducing the water supply temperature to T3 + T. When -T ≤ T2 - T3 ≤ T, the system maintains the default water supply temperature T2 for micro-frost cooling. When T2 - T3 < -T, the system maintains the default water supply temperature T2 for frost cooling. By dynamically adjusting the water supply temperature, the system can accurately and quickly control the temperature inside the dome cover according to actual needs and the frost formation limit, and can adapt to the continuously changing cooling demands inside the dome cover throughout the year.

[0021] In an alternative embodiment, based on the monitoring data of the frost layer thickness of the surface cooler of the dome air-conditioning terminal system, it is determined whether the frost layer thickness of the surface cooler of the dome air-conditioning terminal system is greater than a preset percentage of the half pitch of the fins of the surface cooler; if it is greater than the preset percentage, it is determined whether all the vertical fan coil units in the dome air-conditioning terminal system have switched to defrosting. If all the vertical fan coil units have switched to defrosting, the dome air-conditioning thermal control system shuts down and the dome emergency exhaust system is started. If some of the vertical fan coil units have switched to defrosting, the standby vertical fan coil units of the dome air-conditioning terminal system are started to switch to defrosting, and the dome air-conditioning terminal system continues to supply cooling; if it is less than the preset percentage, the dome air-conditioning terminal system continues to supply cooling.

[0022] Beneficial effects: By monitoring the frost layer thickness of the surface cooler in real time, the system can timely determine whether the frost layer exceeds the preset percentage of the half pitch of the surface cooler fins. When the frost layer is too thick, the system takes corresponding measures to prevent the excessive accumulation of the frost layer from affecting the heat exchange efficiency of the surface cooler and ensure the normal operation of the system. If the frost layer thickness exceeds the preset percentage, the system will determine whether all the vertical fan coil units are transferred to defrosting. If so, the dome emergency exhaust system will be started to avoid the interruption of cooling caused by defrosting and ensure the stable operation of the telescope equipment. If not, that is, when some vertical fan coil units are transferred to defrosting, the system will start the standby vertical fan coil units to ensure continuous cooling of the dome air-conditioning terminal system. The reliability of the system is improved, and the reduction of cooling capacity caused by defrosting of some units is avoided. When the frost layer thickness is less than the preset percentage, the system will continue to cool, avoiding unnecessary defrosting operations, reducing energy waste and improving the energy efficiency of the system.

[0023] In an optional embodiment, the dome emergency exhaust system includes an openable telescope dome, a large-volume exhaust fan and an electric sealing device. Among them, the large-volume exhaust fans are evenly arranged on the annular wall at the bottom of the dome and are used to exhaust air quickly at a preset wind speed; the openable telescope dome is used to open the telescope dome cover to accelerate air flow; the electric sealing device is used to ensure the airtightness of the cover when the dome emergency exhaust system is not started.

[0024] Beneficial effects: The openable telescope dome can be quickly opened under special circumstances (such as the failure of the air-conditioning thermal control system or the predicted target temperature deviating greatly from the actual value and the dome air-conditioning terminal adjusting untimely), ventilated at a preset wind speed, and can reduce the temperature inside the dome cover in a short time. The large-volume exhaust fans are evenly arranged on the annular wall at the bottom of the dome, which can accelerate the air flow inside the dome cover, enhance the ventilation effect, significantly improve the cooling efficiency, and ensure that the temperature inside the dome cover can be quickly reduced to the target range under special circumstances. The electric sealing device can be closed when the system is not started to prevent external dust, moisture or other pollutants from entering the dome cover, ensuring the cleanliness and stability of the telescope observation environment. As a backup plan, the dome emergency exhaust system can be quickly started when the air-conditioning thermal control system fails to quickly meet the working temperature requirements of the telescope. Description of the Drawings

[0025] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1Schematic diagram of the thermal control system inside the dome cover of the large-aperture telescope of the present invention;

[0027] Figure 2 Flow chart of the temperature control strategy for the cold source water supply of the present invention.

[0028] Description of the reference numerals in the drawings:

[0029] 1. Thermal control system of the dome air conditioner; 11. Terminal system of the dome air conditioner; 12. Cold source distribution system; 13. Stepless variable temperature cold source system; 131. Wide temperature range variable temperature cooling equipment; 1311. Stepless temperature control type normal temperature cold source unit; 1312. Stepless temperature control type low temperature cold source unit; 1313. Stepless temperature control type ultra-low temperature cold source unit; 132. Refrigeration guarantee equipment for low ambient temperature; 1321. Split type condensation and heat dissipation equipment; 1322. Duty heating equipment; 1323. Anti-freezing heat exchange medium. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] Good pointing accuracy and imaging quality are inevitable requirements for an optical telescope to maximize its scientific benefits. As the aperture of the telescope continues to increase, the thermal inertia of each component of the system increases accordingly, and the adverse impact of local seeing caused by the temperature change lag of each component on the imaging accuracy of the optical system becomes more and more obvious. Research shows that when the temperature difference between the telescope surface and the surrounding environment is too large, the convective heat exchange between the two will cause frequent changes in the air refractive index within the light path range, resulting in the movement and distortion of the observed image plane; on the premise that the site conditions, telescope performance, terminal instrument equipment, etc. have been basically determined, the improvement measures and observation strategies for local seeing will significantly affect the imaging quality of the telescope. Therefore, adopting necessary thermal control means to control the temperature difference inside and outside the dome of a large-aperture optical telescope has become a key link in the application of such devices.

[0032] Different from the indoor set temperature of a conventional air-conditioning system being almost constant, the dome thermal control system needs to adjust its set temperature according to the outdoor ambient temperature at the predicted uncovering time every day. Since the outdoor temperature varies greatly throughout the year, this poses extremely high requirements for the adjustment ability and environmental adaptability of the thermal control system. In related technologies, the focus of the thermal control system design is on the airflow improvement design, and the problem of full-time guarantee of the thermal environment inside the dome of a large-aperture telescope has not been solved. The present invention provides a thermal control system inside the dome of a large-aperture telescope to solve the problem of full-time guarantee of the thermal environment inside the dome of a large-aperture telescope.

[0033] The following will describe the embodiments of the present invention in conjunction with Figures 1 to 2 .

[0034] According to an embodiment of the present invention, there is provided a thermal control system inside the dome of a large-aperture telescope, including: a dome air-conditioning thermal control system 1 and a dome emergency exhaust system. Among them, the dome air-conditioning thermal control system 1 has variable-temperature cooling and preset low-environment-temperature cooling functions, and is used to adjust the thermal environment inside the dome based on preset thermal control requirements; the dome emergency exhaust system is used to perform rapid cooling adjustment when the adjustment effect of the dome air-conditioning thermal control system 1 cannot meet the preset thermal control requirements.

[0035] In some embodiments, the preset thermal control requirement is to rapidly reduce the temperature inside the telescope dome to the predicted target temperature. The embodiments of the present invention dynamically adjust the cold source temperature and adopt corresponding low-environment-temperature cooling guarantee measures to meet the continuously changing cooling requirements of the large-aperture telescope throughout the year, ensure that such scientific devices can quickly reach the working environment requirements at any time throughout the year, significantly reduce the observation preparation time of the telescope, and improve its scientific benefits.

[0036] In conjunction with Figure 1 shown, the dome air-conditioning thermal control system 1 includes a dome air-conditioning terminal system 11, a stepless variable-temperature cold source system 13, and a cold source distribution system 12; the dome air-conditioning terminal system 11 is directly arranged in the main mirror room of the telescope and can quickly respond to temperature changes and accurately adjust the thermal environment inside the dome. Through the wide-temperature-range variable-temperature refrigerant provided by the stepless variable-temperature cold source system 13, the system can flexibly adjust the cooling temperature according to actual needs, avoid the influence of temperature deviation on the telescope optical system, and thus improve the accuracy of observation data and the image quality.

[0037] The stepless variable temperature cold source system 13 can provide a wide-temperature-range refrigerant that meets the annual cooling demand and adapts to the changes in different seasons and ambient temperatures. Whether in the high-temperature summer or the low-temperature winter, the system can provide appropriate cooling capacity to ensure that the telescope always operates within the optimal temperature range. The cold source distribution system 12 realizes the efficient circulation of the refrigerant between the stepless variable temperature cold source system 13 and the dome air-conditioning terminal system 11 through circulating pumps, circulating pipelines and their accessories, optimizes the conveying efficiency of the refrigerant, reduces energy loss, lowers the operating energy consumption, and meets the requirements of energy conservation and environmental protection.

[0038] The cold source distribution system 12 adopts reliable circulating pumps, pipelines and accessories to ensure the stability and continuity of the refrigerant circulation. The dome air-conditioning thermal control system 1 has the functions of variable temperature cooling and preset low ambient temperature cooling, and can accurately adjust the temperature environment inside the dome according to the thermal control requirements during the operation of the telescope. It helps to reduce the influence of temperature deviation on the telescope optical system, ensures the accuracy and stability of the observation data, and can flexibly adjust the cooling mode according to different ambient temperatures and observation requirements.

[0039] In some embodiments, in combination with Figure 1 As shown, the dome air-conditioning terminal system 11 is arranged in the main mirror room of the telescope and is used to adjust the temperature inside the dome; the dome air-conditioning terminal system 11 includes vertical fan coil units, which are placed on the ground of the main mirror room and are evenly arranged in a ring along the outer wall of the main mirror room. They are connected to the stepless variable temperature cold source system 13 through the cold source distribution system 12, and both the running units and standby units of the vertical fan coil units are configured.

[0040] The vertical fan coil units of the embodiments of the present invention are evenly arranged in a ring along the outer wall of the main mirror room, which can achieve uniform adjustment of the temperature inside the main mirror room, avoid local overheating or overcooling, thereby reducing the thermal deformation and local seeing caused by uneven temperature of the telescope optical system, and thus improving the observation accuracy. The vertical fan coil units are directly arranged on the ground of the main mirror room, close to the heat source, and can quickly absorb and disperse heat to achieve efficient cooling. The running units and standby units are configured together, and each running unit is equipped with a standby unit. When the running unit fails or needs maintenance, the standby unit can be immediately put into use to ensure the uninterrupted operation of the system and improve the reliability and stability of the system. Specifically, the dome air-conditioning terminal system 11 is a vertical fan coil unit, with a total of 8 units, 4 in use and 4 as spares, placed on the ground of the main mirror room and evenly arranged in a ring along the outer wall. It is connected to the stepless variable temperature cold source system 13 through the cold source distribution system 12.

[0041] In some embodiments, in combination with Figure 1As shown in the figure, the stepless variable-temperature cold source system 13 is used to provide a wide-temperature-range variable-temperature refrigerant that meets the annual cooling demand for the dome air-conditioning terminal system 11; the stepless variable-temperature cold source system 13 includes a wide-temperature-range variable-temperature cooling equipment 131 and a low-environment-temperature refrigeration guarantee equipment 132. The wide-temperature-range variable-temperature cooling equipment 131 is composed of multiple parallel-connected stepless variable-temperature cold source units, which can provide a large range of water supply temperature regulation, enabling the system to adapt to different seasons, different ambient temperatures, and different thermal control requirements of the telescope, ensuring that the temperature inside the dome is always within the optimal range. By arranging multiple stepless variable-temperature cold source units in parallel, when one of the units fails, the other units can still continue to operate, ensuring uninterrupted cooling of the system. The low-environment-temperature refrigeration guarantee equipment 132 is used to ensure the reliable operation of the stepless variable-temperature cold source units in low-temperature environments. Through the cooperation of the wide-temperature-range variable-temperature cooling equipment 131 and the low-environment-temperature refrigeration guarantee equipment 132, the system can achieve stable cooling throughout the year, ensuring that the telescope always operates within the optimal temperature range.

[0042] The wide-temperature-range variable-temperature cooling equipment 131 is arranged in the cold source machine room and is composed of multiple parallel-connected stepless variable-temperature cold source units for water supply temperature regulation. The wide-temperature-range variable-temperature cooling equipment 131 can achieve a large range of water supply temperature regulation by changing the input power of the variable-frequency compressor, the opening of the electronic expansion valve, the bypass water flow, unit switching, etc. The wide-temperature-range variable-temperature cooling equipment 131 includes a stepless temperature-regulating normal-temperature cold source unit 1311, whose water temperature regulation range is the first temperature range; a stepless temperature-regulating low-temperature cold source unit 1312, whose water temperature regulation range is the second temperature range; a stepless temperature-regulating ultra-low-temperature cold source unit 1313, whose water temperature regulation range is the third temperature range; the temperature in the first temperature range is greater than the temperature in the second temperature range, the temperature in the second temperature range is greater than the temperature in the third temperature range, and each type of unit is configured with both an operating unit and a standby unit, and each of the operating units is equipped with one of the standby units.

[0043] The equipment covers the cooling demand in a wide temperature range from normal temperature to ultra-low temperature through three types of cold source units, and can flexibly respond to different seasons, different ambient temperatures and different thermal control requirements of the telescope, ensuring that the temperature inside the dome is always within the optimal range. Each type of cold source unit is configured with an operating unit and a standby unit, that is, each operating unit is equipped with a standby unit, ensuring that when the operating unit fails or needs maintenance, the standby unit can be immediately put into use to ensure uninterrupted cooling of the system, significantly improving the reliability and stability of the system. Specifically, to meet the cooling demand of 7°C to -35°C, the wide-temperature variable-temperature cooling equipment 131 includes 2 stepless temperature-regulating normal-temperature screw chillers (the water supply temperature regulation range is 7°C to -10°C), 2 stepless temperature-regulating low-temperature screw chillers (the water supply temperature regulation range is -10°C to -25°C), and 2 stepless temperature-regulating ultra-low-temperature screw chillers (the water supply temperature regulation range is -25°C to -35°C), all of which are 1 for 1 standby.

[0044] The low ambient temperature refrigeration guarantee equipment 132 is used to guarantee the reliable operation of the stepless variable-temperature cold source unit in low ambient temperature. The low ambient temperature refrigeration guarantee equipment 132 includes a split-type condensation and heat dissipation equipment 1321, a duty heating equipment 1322 and an anti-freeze heat exchange medium 1323. Among them, the split-type condensation and heat dissipation equipment 1321 is arranged on the roof of the cold source machine room. The split-type condensation and heat dissipation equipment 1321 is arranged corresponding to the stepless variable-temperature cold source unit one by one. The split-type condensation and heat dissipation equipment 1321 is connected to the stepless variable-temperature cold source unit through a cooling water pipeline, and is used to maintain the condensation pressure required for the normal operation of each cold source unit; the duty heating equipment 1322 is evenly arranged along the outer wall of the cold source machine room to ensure that the working environment temperature of the wide-temperature variable-temperature cooling equipment 131 is not lower than the preset temperature; the anti-freeze heat exchange medium 1323 is arranged in the circulation pipeline.

[0045] The split-type condensation and heat dissipation equipment 1321 is arranged on the roof of the cold source machine room, corresponding to the stepless variable-temperature cold source unit one by one, and is connected through a cooling water pipeline. The split-type condensation and heat dissipation equipment 1321 can effectively maintain the condensation pressure and ensure the stable operation of the cold source unit in a low-temperature environment. The duty heating equipment 1322 is evenly arranged along the outer wall of the cold source machine room, which can ensure that the working environment temperature of the wide-temperature variable-temperature cooling equipment 131 is not lower than the preset temperature, avoiding the damage of the low-temperature environment to the cold source unit and its auxiliary equipment, and extending the service life of the equipment.

[0046] Specifically, the split-type condensation heat dissipation device 1321 adopts closed cooling towers, a total of 6 units, which correspond one-to-one with the wide-temperature variable-temperature cooling device 131 and are installed on the roof of the cold source machine room. They are connected to the main body of the cold source unit through cooling water pipelines. During winter operation, the spray system of the closed cooling tower is emptied and operates in a dry condition. By controlling the rotation speed of the heat dissipation fan, the opening degree of the inlet air valve, and the cooling water flow rate of the condenser, etc., the condensation pressure required for the normal operation of the cold source unit is maintained. A duty heating device 1322 is set in the cold source machine room. It is an electric heater with a rated power of 2 kW, a total of 5 units, which are evenly arranged along the outer wall of the cold source machine room to ensure that the working environment temperature of the wide-temperature variable-temperature cooling device 131 is not lower than 5 °C. Among them, 5 °C is the duty heating temperature commonly used in the project, taking into account anti-freezing, energy conservation, safety margin, and technical feasibility.

[0047] The anti-freezing heat exchange medium 1323 is arranged in the circulation pipeline and can prevent the liquid in the pipeline from freezing in a low-temperature environment, ensuring the fluidity of the cooling water or refrigerant in the circulation pipeline and avoiding system interruption or equipment damage caused by pipeline freezing. Through the combined action of the split-type condensation heat dissipation device 1321, the duty heating device 1322, and the anti-freezing heat exchange medium 1323, the system can maintain normal operation in an extremely low-temperature environment to ensure uninterrupted cooling throughout the year. Specifically, the anti-freezing heat exchange medium 1323 is selected from anti-freezing secondary refrigerants or anti-freezing coolants. The main function of the anti-freezing secondary refrigerant is to act as a secondary refrigerant in a low-temperature environment and transfer the cold generated by the refrigeration system to the places or equipment that need to be cooled. It has a relatively low freezing point and can remain liquid at low temperatures, preventing problems such as pipeline blockage and equipment damage caused by freezing. Coolants are generally used to prevent damage caused by overheating. In some cooling systems that may face low-temperature environments, the coolant also needs to have anti-freezing performance to ensure normal circulation and cooling effect in cold conditions. The anti-freezing heat exchange medium 1323 adopts a modified ethylene glycol aqueous solution with a volume concentration of 55%, and its freezing point is more than 5 °C lower than the lowest possible operating temperature of the system. The standard of more than 5 °C refers to the duty heating temperature setting principle, taking into account actual needs and safety and reliability.

[0048] In some embodiments, in combination with Figure 1 As shown, the cold source distribution system 12 is used to connect the stepless variable-temperature cold source system 13 and the dome air-conditioning terminal system 11 to realize the circulation of the refrigerant between the two, including a circulation water pump, a circulating refrigerant, a circulation pipeline, and its accessories.

[0049] In some embodiments, in combination with Figure 1As shown, the dome emergency exhaust system, as a backup solution, can be quickly activated and perform rapid cooling adjustment when the air-conditioning thermal control system fails to meet the thermal control requirements. This emergency mechanism ensures that the telescope can quickly reach a suitable operating temperature in extreme weather or emergencies. The dome emergency exhaust system includes an openable telescope dome, high-volume exhaust fans, and an electric sealing device. Among them, the high-volume exhaust fans are evenly arranged on the ring wall at the bottom of the dome and are used to quickly exhaust air at a preset wind speed; the openable telescope dome is used to open the telescope dome cover to accelerate air flow; the electric sealing device is used to ensure the airtightness of the cover when the dome emergency exhaust system is not activated.

[0050] The openable telescope dome can be quickly opened in emergencies (such as when the air-conditioning thermal control system fails or there is a high heat load), ventilated at a preset wind speed, and can reduce the temperature inside the dome cover in a short time to prevent damage to the telescope equipment due to overheating. The high-volume exhaust fans are evenly arranged on the ring wall at the bottom of the dome, which can accelerate the air flow inside the dome cover and enhance the ventilation effect. This significantly improves the cooling efficiency and ensures that the temperature inside the dome cover can quickly reach the observation requirements in an emergency. The electric sealing device can be closed when the system is not activated to prevent external dust, moisture, or other pollutants from entering the dome cover, ensuring the cleanliness and stability of the telescope observation environment and the accuracy of the observation data and the image quality. The dome emergency exhaust system, as a backup solution, can be quickly activated when the air-conditioning thermal control system fails to ensure that the temperature inside the dome cover meets the operating requirements.

[0051] Specifically, the exhaust air of the dome emergency exhaust system is directly discharged to the atmosphere through the outer wall. When the system is activated, it can provide no less than 20 air changes per hour for the dome. By cooperating with opening the movable top cover of the dome for air supply, the outside air can directly wash the telescope to accelerate its heat balance with the outside world. When the telescope is observing, the dome emergency exhaust system is closed to avoid the deterioration of the telescope's seeing caused by the disturbance of high-speed air flow.

[0052] In some embodiments, combined with Figure 2 As shown, a cold source water supply temperature control strategy is adopted to accurately adjust the set water supply temperature of the cold source unit, realizing frost-free or light-frost cooling of the dome air-conditioning terminal system 11 and meeting the continuous cooling demand. When the wide-temperature zone variable-temperature cooling device 131 adjusts the water supply temperature, it determines the initial water supply temperature T2 of the stepless variable-temperature cold source unit according to the predicted target temperature T1 inside the dome cover, T2 = T1 - T', where T' represents the temperature difference value that meets the cooling demand of the dome air-conditioning terminal system 11; the water supply temperature is dynamically adjusted according to the temperature difference between the inlet air dew point T3 of the dome air-conditioning terminal system 11 and the initial water supply temperature T2.

[0053] The system determines the initial water supply temperature T2 according to the predicted target temperature T1 inside the dome cover through the formula T2 = T1 - T', ensuring that the water supply temperature can meet the cooling demand of the dome air-conditioning terminal system 11, avoiding the problems of insufficient cooling or over-cooling caused by temperature deviation in the traditional cold source system, and significantly improving the thermal control effect. According to the temperature difference between the inlet air dew point T3 of the dome air-conditioning terminal system 11 and the initial water supply temperature T2, the water supply temperature is dynamically adjusted, enabling the system to respond in real time to the temperature changes inside the dome cover and ensuring that the thermal environment is always within the optimal range. Dynamically adjusting the water supply temperature can effectively reduce the impact of temperature deviation on the telescope optical system and improve the stability of the system.

[0054] Dynamically adjusting the water supply temperature includes: when T2 - T3 > T, where T represents the temperature difference threshold, reducing the water supply temperature to T3 + T °C for rapid cooling with a large temperature difference; when -T ≤ T2 - T3 ≤ T, maintaining the default water supply temperature T2 for micro-frost cooling; when T2 - T3 < -T, maintaining the default water supply temperature T2 for frost cooling. By dynamically adjusting the water supply temperature, the system can accurately control the temperature inside the dome cover according to actual needs and avoid the impact of temperature deviation on the telescope optical system.

[0055] In one embodiment, T' is 6.5 °C, which is the minimum temperature difference to meet the cooling demand of the dome air-conditioning terminal system 11; T is 2 °C, which is a buffer zone set considering the fluctuations of the actual water supply temperature and the inlet air dew point temperature. It is found in actual engineering that within this range, the frosting speed is slower due to the small gap between the cold surface temperature and the inlet air dew point.

[0056] In this embodiment, a cold source water supply temperature control strategy is adopted for the dome air-conditioning thermal control system to accurately adjust the set water supply temperature of the stepless variable temperature cold source unit, achieve frost-free or light-frost cooling of the dome air-conditioning terminal system, meet the continuous cooling demand, combined with Figure 2 As shown, since there is a risk that the cold source unit may stop due to severe frosting on the fin of the surface cooler of the dome air-conditioning terminal, it is necessary to judge whether the frosting thickness of the surface cooler of the dome air-conditioning terminal system 11 is greater than the preset percentage of half the fin pitch of the surface cooler according to the monitoring data of the frosting thickness of the surface cooler of the dome air-conditioning terminal system 11; if it is greater than the preset percentage, it is judged whether all the vertical fan coil units in the dome air-conditioning terminal system 11 have switched to defrosting. If all the vertical fan coil units have switched to defrosting, the dome air-conditioning thermal control system 1 stops and the dome emergency exhaust system is started. If some vertical fan coil units have switched to defrosting, the standby vertical fan coil units of the dome air-conditioning terminal system 11 are started to switch to defrosting, and the dome air-conditioning terminal system 11 continues to supply cooling; if it is less than the preset percentage, the dome air-conditioning terminal system 11 continues to supply cooling.

[0057] By monitoring the frost layer thickness of the surface cooler in real time, the system can timely determine whether the frost layer exceeds the preset percentage of the half pitch of the fins of the surface cooler. When the frost layer is too thick, the system takes corresponding measures to prevent the excessive accumulation of the frost layer from affecting the heat exchange efficiency of the surface cooler and ensure the normal operation of the system. If the frost layer thickness exceeds the preset percentage, the system will judge whether all vertical fan coil units are transferred to defrost. If so, the dome emergency exhaust system is started, avoiding the interruption of cooling caused by defrost and ensuring the stable operation of the telescope equipment. If not, that is, when some vertical fan coil units are transferred to defrost, the system will start the standby vertical fan coil units to ensure the continuous cooling of the dome air conditioning terminal system 11, that is, the main and backup (4 units each) dome air conditioning terminal systems 11 work in a round-robin manner for defrosting to continuously cool the dome. This improves the reliability of the system and avoids the reduction of cooling capacity caused by the defrost of some units. When the frost layer thickness is less than the preset percentage, the system will continuously cool, avoiding unnecessary defrost operations, reducing energy waste and improving the energy efficiency of the system.

[0058] Specifically, the preset percentage is 60%. On the one hand, the frost layer thermal resistance will significantly reduce the heat transfer coefficient on the surface of the surface cooler. On the other hand, the frost layer will significantly reduce the air flow cross-sectional area between the fins, resulting in a sharp drop in air flow. When the frost layer thickness reaches 60% or more, frost bridges may occur on some fins, accelerating the frosting speed. Therefore, the preset percentage is set to 60%.

[0059] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. Although the embodiments of the present invention are described in conjunction with the drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the present invention.

Claims

1. A thermal control system inside the dome cover of a large-aperture telescope, characterized in that, Comprising: A dome air-conditioning thermal control system (1), having the functions of variable-temperature cooling and preset low ambient temperature cooling, and being used to adjust the thermal environment inside the dome based on preset thermal control requirements; A dome emergency exhaust system, which is used for rapid cooling adjustment when the adjustment effect of the dome air-conditioning thermal control system (1) cannot meet the preset thermal control requirements.

2. The thermal control system inside the dome cover of the large-aperture telescope according to claim 1, characterized in that, The dome air-conditioning thermal control system (1) includes: A dome air-conditioning terminal system (11), which is arranged in the main mirror room of the telescope and is used to adjust the temperature inside the dome; A stepless variable-temperature cold source system (13), which is used to provide a wide-temperature-range variable-temperature refrigerant that meets the annual cooling demand for the dome air-conditioning terminal system (11); A cold source distribution system (12), which is used to connect the stepless variable-temperature cold source system (13) and the dome air-conditioning terminal system (11) to realize the circulation of the refrigerant between the two, and includes a circulation water pump, a circulating refrigerant, a circulation pipeline and its accessories.

3. The thermal control system inside the dome cover of the large-aperture telescope according to claim 2, characterized in that, The dome air-conditioning terminal system (11) includes: Vertical fan coil units, which are placed on the ground of the main mirror room and are arranged in a ring shape along the outer wall of the main mirror room. They are connected to the stepless variable-temperature cold source system (13) through the cold source distribution system (12), and both the running units and standby units are configured for the vertical fan coil units.

4. The thermal control system inside the dome cover of the large-aperture telescope according to claim 2, characterized in that, The stepless variable-temperature cold source system (13) includes: A wide-temperature-range variable-temperature cooling equipment (131), which is arranged in the cold source machine room and consists of multiple stepless variable-temperature cold source units connected in parallel, and is used for adjusting the water supply temperature; A low ambient temperature refrigeration guarantee equipment (132), which is used to ensure the reliable operation of the stepless variable-temperature cold source units under low ambient temperature.

5. The thermal control system inside the dome cover of the large-aperture telescope according to claim 4, wherein, The wide-temperature-range variable-temperature cooling equipment (131) includes: A stepless temperature-adjustable normal temperature cold source unit (1311), whose water temperature adjustment range is the first temperature range; A stepless temperature-adjustable low temperature cold source unit (1312), whose water temperature adjustment range is the second temperature range; A stepless temperature-adjustable ultra-low temperature cold source unit (1313), whose water temperature adjustment range is the third temperature range; The temperature in the first temperature range is greater than the temperature in the second temperature range, the temperature in the second temperature range is greater than the temperature in the third temperature range, and both the running units and standby units are configured for each type of unit.

6. The thermal control system inside the dome cover of the large-aperture telescope according to claim 4, characterized in that, The low ambient temperature refrigeration guarantee equipment (132) includes: A split-type condensation heat dissipation equipment (1321), which is arranged on the roof of the cold source machine room. The split-type condensation heat dissipation equipment (1321) is arranged corresponding to the stepless variable-temperature cold source units one by one, and the split-type condensation heat dissipation equipment (1321) is connected to the stepless variable-temperature cold source units through cooling water pipelines, and is used to maintain the condensation pressure required for the normal operation of each cold source unit; Duty heating equipment (1322), which is evenly arranged along the outer wall of the cold source machine room to ensure that the working environment temperature of the wide-temperature-range variable-temperature cooling equipment (131) is not lower than the preset temperature; An anti-freezing heat exchange medium (1323), which is arranged in the circulation pipeline, and its freezing point is lower than the lowest operating temperature of the system.

7. The thermal control system inside the dome cover of the large-aperture telescope according to claim 4, wherein, When the wide-temperature-range variable-temperature cooling equipment (131) adjusts the water supply temperature, Determine the initial water supply temperature T2 of the stepless variable temperature cold source unit according to the predicted target temperature T1 inside the dome cover, where T2 = T1 - T', and T' represents the temperature difference value that meets the cooling demand of the dome air-conditioning terminal system (11); Dynamically adjust the water supply temperature according to the temperature difference between the inlet air dew point T3 of the dome air-conditioning terminal system (11) and the initial water supply temperature T2.

8. The thermal control system inside the dome cover of the large-aperture telescope according to claim 7, characterized in that The dynamic adjustment of the water supply temperature includes: When T2 - T3 > T, where T represents the temperature difference threshold, reduce the water supply temperature to T3 + T for rapid cooling with a large temperature difference; when -T ≤ T2 - T3 ≤ T, maintain the initial water supply temperature T2 for micro-frost cooling; when T2 - T3 < -T, maintain the initial water supply temperature T2 for frost cooling.

9. The thermal control system inside the dome cover of the large-aperture telescope according to claim 2, characterized in that, Judge whether the frost layer thickness of the finned tube heat exchanger of the dome air-conditioning terminal system (11) is greater than the preset percentage of half the pitch of the finned tube heat exchanger according to the monitored data of the frost layer thickness of the finned tube heat exchanger of the dome air-conditioning terminal system (11); If it is greater than the preset percentage, judge whether all the vertical fan coil units in the dome air-conditioning terminal system (11) have switched to defrosting. If all the vertical fan coil units have switched to defrosting, the dome air-conditioning thermal control system (1) shuts down and the dome emergency exhaust system is started. If some of the vertical fan coil units have switched to defrosting, start the standby vertical fan coil units of the dome air-conditioning terminal system (11) to switch to defrosting, and the dome air-conditioning terminal system (11) continues to supply cooling; If it is less than the preset percentage, the dome air-conditioning terminal system (11) continues to supply cooling.

10. The thermal control system inside the dome cover of the large-aperture telescope according to claim 1, characterized in that, The dome emergency exhaust system includes: High-volume exhaust fans, which are evenly arranged on the annular wall at the bottom of the dome and are used to exhaust air quickly at a preset wind speed; An openable telescopic dome, which is used to open the dome cover to accelerate air flow; An electric sealing device, which is used to ensure the airtightness of the cover when the dome emergency exhaust system is not started.

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