CO2 Heat Pump Efficiency (Ejector) Patent Snapshot
This is a small, China-dominated niche: the corpus stands at 33 patent families, with Chinese institutions holding the top positions and China accounting for the largest share of filing activity. The field reached its peak around 2019 and has since plateaued, with the top five filers controlling 60% of the hundred largest filers’ combined total—signaling high concentration and limited open ground in the core F25B refrigeration class.
Xi’an Jiaotong University and China National Energy Refining & Chemical Engineering Co. share the lead in a concentrated niche
Xi’an Jiaotong University and. China National Energy Refining & Chemical Engineering Co. are tied at the top of the applicant ranking, each holding 7 patent records, followed closely by Qingdao Haier Smart Technology R&D Co. with 6 patent records.
The top five filers account for 60% of the ranked applicants visible in this query’ combined total, indicating a tightly held competitive space. A visible tier gap separates the three leading organisations from the remaining applicants, most of whom hold only 1–2 patent records.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Xi’an Jiaotong University | 7 | |
| 2 | CHINA NAT ENERGY REFINING & CHEM ENG CO LTD | 7 | |
| 3 | QINGDAO HAIER SMART TECH R & D CO LTD | 6 | |
| 4 | Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences | 3 | |
| 5 | Ningbo Saisen Energy Saving Equipment Co., Ltd. | 2 | |
| 6 | Sadigh Tehrani Shahin SS | 2 | |
| 7 | Tianjin University | 2 | |
| 8 | China Metallurgical Technology Achievement Transfer Co., Ltd. | 1 | |
| 9 | Gansu Yide New Energy Equipment Co. | 1 | |
| 10 | SHAANXI UNIV OF SCI & TECH | 1 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | SmartHeat Shenyang Heat Pump Technology Co., Ltd. | 1 | |
| 12 | PetroChina Co., Ltd. | 1 | |
| 13 | PetroChina Shenzhen New Energy Research Institute | 1 | |
| 14 | Tianjin University of Commerce | 1 | |
| 15 | Shanghai Ocean University | 1 | |
| 16 | Dalian Baoguang Energy Saving Air Conditioning Equipment Co. | 1 | |
| 17 | Bair Refrigeration (Wuxi) Co., Ltd. | 1 | |
| 18 | Shandong Shenzhou Refrigeration Equipment Co. | 1 | |
| 19 | Indian Institute of Technology Bombay | 1 | |
| 20 | Dongfeng Motor Group Co., Ltd. | 1 |
The co-presence of a university (Xi’an Jiaotong University), an energy engineering enterprise (China National Energy Refining & Chemical Engineering Co.), and a consumer appliance R&D unit (Qingdao Haier Smart Technology R&D Co.) at the top signals that ejector-based CO2 heat pump efficiency spans both heavy-industry and consumer-product development tracks.
Patent records filed in the most recent 18–24 months are subject to publication lag and may understate actual filing activity; the 2025–2026 data should be read as provisional. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Activity peaked in 2019 and has since plateaued; F25B refrigeration dominates the technology mix
The annual filing trend and technology composition charts together show a field that expanded quickly to a 2019 peak and has since stabilised, with its technological core firmly anchored in IPC class F25B.
Annual filing trend
Filings surged from 4 patent records in 2018 to a peak of 9 in 2019, then fell sharply before recovering to a range of 3–5 records per year through 2023–2025. The lifecycle evidence confirms annual volume has eased from the 2019 peak and plateaued; data for 2025–2026 are subject to publication lag and should not be read as a further decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
F25B (Refrigeration & Heat Pumps) accounts for 42 patent records—by far the visible class—confirming that ejector integration work is concentrated in core refrigeration cycle design. Secondary classes including F24D (Domestic Heating Systems, 5 records), F01K (Steam & Thermal Power Plants, 4 records), and F24F (Air Conditioning & Ventilation, 4 records) are each present at low volumes, pointing to emerging multi-application interest.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
CO2 Heat Pump System or CO2 Refrigeration System C…
A CO<sub>2 </sub>based system, such as a heat pump system or a refrigeration system, is disclosed. The system comprises a plurality of ejectors arranged in parallel. Each of the ejectors comprises a motive port and a suction port. Each of the ejectors has a fixed geometry. A first actuated ball valve is arranged in front of the motive port. A second… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | 一种用于内燃机余热回收的CO2循环多联产系统 | 22 |
| 2 | 一种暖气片供暖用跨临界CO2热泵系统 | 19 |
| 3 | 一种背压喷射式跨临界CO2动力循环发电系统 | 17 |
| 4 | 一种空气源CO2热泵蒸汽机组 | 9 |
| 5 | 一种以二氧化碳为制冷工质的热泵循环多功能机组 | 8 |
| 6 | 一种引射器增压过冷膨胀机耦合跨临界CO<sub>2</sub>系统 | 6 |
| 7 | 一种引射器增压过冷膨胀机耦合跨临界CO<sub>2</sub>系统及应用 | 4 |
| 8 | 一种尾气余热回收系统 | 4 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
Assignee snapshot from the current evidence set
The applicants below are visible in this query result. Because the evidence set is relatively small, read this section as a directional snapshot rather than a full competitive ranking.
Xi’an Jiaotong University
Xi’an Jiaotong University holds 7 patent records, tied for the top position. Its technology focus spans F25B 9 (refrigeration cycle fundamentals), F25B 41 (control and flow components), and F01D 15 (turbine-coupled power recovery), indicating a research orientation toward thermodynamic cycle integration and work-recovery mechanisms. Momentum trend is flagged as a new entrant in the recent window, suggesting recent-period filing activity is a fresh push rather than a long-standing programme.
patent records: 7Qingdao Haier Smart Technology R&D Co.
Qingdao Haier Smart Technology R&D Co. holds 6 patent records and is the strongest industry-side filer. Its focus is concentrated in F25B 41, F25B 9, and F25B 13 (cascade and multi-stage refrigeration), reflecting product-level heat pump development. Its momentum trend is also flagged as a new entrant, meaning its current portfolio has been built recently and may still be growing. Its intra-group co-filing with Haier Group signals a pipeline from R&D unit to commercial product.
patent records: 6Frequently asked questions
The corpus in scope covers 33 patent families. This is a small, specialist niche rather than a broad technology domain, which means the competitive dynamics are shaped by a handful of active filers rather than a large distributed field.
Xi’an Jiaotong University and China National Energy Refining & Chemical Engineering Co. are tied at the top with 7 patent records each, followed by Qingdao Haier Smart Technology R&D Co. with 6 patent records. Together the top five filers account for 60% of the ranked applicants visible in this query’ combined total.
The field is at a Maturity stage: annual filings peaked in 2019 at 9 patent records and have since plateaued in a range of 3–5 records per year. The recent-window growth rate is -8%. This indicates the core F25B ejector design space is established, though adjacent application domains remain less developed.
China is visible in with 37 patent records. Canada has 2 records, and Denmark, India, and the United States each have 1. Coverage in major markets such as the EU, Japan, and Korea is near-absent, which may offer freedom-to-operate or licensing opportunities for non-Chinese entrants in those regions.
The only recorded co-applicant relationship is between Qingdao Haier Smart Technology R&D Co. and Haier Group, with 1 joint filing. This is an intra-group pairing reflecting technology transfer within the Haier corporate family. No university–industry co-filings are recorded in the evidence.
F24D (Domestic Heating Systems, 5 patent records), F01K (Steam & Thermal Power Plants, 4 records), F24F (Air Conditioning & Ventilation, 4 records), B60H (Vehicle Heating & A/C, 3 records), and F01D (Turbines & Non-positive Engines, 3 records) are the sparsest adjacent branches. Of these, F24D and B60H have the most plausible technical rationale for ejector-enhanced CO2 cycle adoption.
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Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
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