1 ZL024 A Photothermal Device for Heating Crude Oil in Oilfields (Utility Model) (Science & Technology, Technology) ZL023 A High-Efficiency Photothermal System for Heating Crude Oil in Oilfields (Utility Model) (Science & Technology, Technology) ZL022 An Efficient Photothermal System for Heating and Cooling (Utility Model) (Science & Technology, Technology) ZL021 A CPC Heat-Collecting Skid (Utility Model) (Science & Technology, Technology) ZL016 A High-Efficiency CPC Solar Collector (Utility Model) (Science & Technology) ZL015 A Skid-Mounted Photothermal Circulating Heating Device for Oilfield Well Sites (Utility Model) (Science & Technology, Technology)