Fastest
Eureka on the web
When you want the answer in the next five minutes.
The agent works the prompt against patents and technical literature, citing every source.
Run your analysis now →https://www.patsnap.com/resources/blog/rd-blog/heat-pipe-two-phase-flow-patent-landscape-patent-landscape/ · Patsnap · data cut-off 2026-08-31 · downloaded from the live page
Patent Landscape · Thermal Systems, HVAC & RefrigerationHeat Pipe Two-Phase Flow Patents: Who Files, What They Claim, and Where the Field Is Still Open
A data-led look at heat pipe two-phase flow patents: filing trends since 2015, the concentration of filings among leading assignees, IPC technology composition, receiving-office spread, and the most-cited prior art shapi
3,334
Published Records
15%
Top-5 Share of All Records
-30%
Filing Growth 2021→2024
CN
Leading Jurisdiction
Filing growth = 2021 (156 records) → 2024 (109); 2024 is the last year we treat as complete. Top-5 share = the 5 largest assignees ÷ all 3,334 records in scope (CR5), not the ranked leaders only.
Published byPatsnap Research··6 min readSourced from Patsnap Eureka
Overview
What this landscape covers
Heat pipe two-phase flow patents cover the boiling and condensing behaviour inside sealed heat-transfer devices — the phase-change mechanics that move heat far more efficiently than solid conduction. This dataset draws on 3,334 published records filed between 2015 and 2026 and classified under air conditioning, refrigeration and heat-exchange IPC codes, giving a working view of where claim activity concentrates and where it thins out. Publication lags filing by roughly 18 months, so the most recent filing years in any trend line are still filling in and should be read as provisional rather than declining.
The records span heat-exchange apparatus, refrigeration and heat-pump systems, air conditioning and ventilation, and heat-exchanger detail claims, with a smaller footprint in electronics cooling and domestic heating. Reading the assignee ranking alongside the IPC composition shows both who is active and which technical sub-areas carry the heaviest prior art.
Heat pipe two-phase flow: filing volume and technology composition, 2015-2026
Source: Patsnap Eureka. Assignee ranking and totals. Derived from a Patsnap search on Heat Pipe Two-Phase Flow Patent Landscape covering 2015–2026, data cut-off 2026-08-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
The Data
Filing trends and technology composition
Three views of the same 3,334-record dataset: how filing volume has moved year over year, which IPC subclasses carry the claim density, and where applicants file to protect the technology geographically.
Filing volume, 2017-2026
Filings rose from 184 in 2017 to a peak of 195 in 2020, then eased to 109 by 2024 — a -30% move from 2021's 156, the last span that can be read as complete given publication lag. Figures for 2025 and 2026 are still filling in and understate true filing activity.
Publication lags filing by roughly 18 months, so 2025 onwards are still filling in. Growth rates on this page therefore end at 2024; running them to the last bar would understate the field.
IPC subclass composition
F28D heat-exchange apparatus appears in 54.7% of the 3,334 records, ahead of F25B refrigeration and heat pumps at 41.9%. Air conditioning and ventilation (F24F, 17.8%) and heat-exchanger details (F28F, 16.7%) form the next tier, with electronics assemblies (H05K, 4.2%) and domestic heating (F24D, 2.6%) marking narrower, more specialised pockets. Because records can carry multiple IPC codes, these shares add to more than 100% of the record total.
Shares are the percentage of the 3,334 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Source: Patsnap Eureka. Filing trend and technology composition. Derived from a Patsnap search on Heat Pipe Two-Phase Flow Patent Landscape covering 2015–2026, data cut-off 2026-08-31. Counts reflect published records only and shift as new filings publish.
Go deeper on Heat Pipe Two-Phase Flow Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about heat pipe two-phase flow patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaKey Patents
Representative filing and most-cited prior art
Representative Record
CN208431895U — Cooling device based on an organic reflux condenser tube
西北民族大学
Filed by Northwest Minzu University in 2019, this utility model describes a cooling device built around a base, water tank and organic reflux condenser tube, with a semiconductor cooling plate used to lower the water temperature inside the tank. Inlet and outlet ports are fitted with screw-mounted pipes and valves, and a drive motor connected through a bearing and coupling turns a first rotating shaft mounted through the tank's top wall.Abstract translated and condensed from the original filing for readability.
Most-cited records in this dataset
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5203399A | Heat transfer apparatus | 205 |
| 2 | US4118756A | Heat pipe thermal mounting plate for cooling electronic circuit cards | 145 |
| 3 | US7210832B2 | Illumination apparatus of light emitting diodes and method of heat dissipation thereof | 127 |
| 4 | US3517730A | Controllable heat pipe | 119 |
| 5 | US5560423A | Flexible heat pipe for integrated circuit cooling apparatus | 118 |
| 6 | US6269865B1 | Network-type heat pipe device | 112 |
| 7 | US20140165570A1 | Oscillating heat pipe for thermal management of gas turbine engines | 102 |
| 8 | US4170262A | Graded pore size heat pipe wick | 102 |
| 9 | US5771967A | Wick-interrupt temperature controlling heat pipe | 99 |
| 10 | US5732562A | Method and apparatus for regenerating desiccants in a closed cycle | 98 |
Citation counts reflect influence within the searched corpus and favour older documents; they are not a measure of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
Source: Patsnap Eureka. Citation counts and representative records. Derived from a Patsnap search on Heat Pipe Two-Phase Flow Patent Landscape covering 2015–2026, data cut-off 2026-08-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
Run it yourself
Put your own technology through the same analysis
Where to run it
For builders
MCP server & REST API
When it has to run inside your own pipeline.
Patent search, landscape analysis and assignee resolution as MCP tools. Drop them into any agent framework, or call REST directly.
Browse MCP servers →Insights
What the numbers say about this field
Four figures from the dataset that matter for deciding where to file, who to watch, and what is already crowded.
Concentration
21.2% of 3,334
held by the top 10 ranked assignees
Leadership is real but not dominant
The leading assignee holds 162 records and the tenth-ranked holds 33, yet the top 10 combined still account for only 21.2% of all 3,334 records in scope. That leaves close to four-fifths of the field spread across a long tail of smaller filers, which is unusual for a mechanically mature technology.
Ranking covers 100 companies, not a top-50 or top-100 cutoff.
Filing momentum
-30% (2021→2024)
the only complete-year growth figure available
Volume has cooled from its 2020 peak
Filings peaked at 195 in 2020, then fell from 156 in 2021 to 109 in 2024 — a decline the dataset itself measures at -30% over that span. Because publication lags filing by around 18 months, 2025 and 2026 figures are still incomplete and should not be read as continuing the same trend.
2024 is the most recent year treated as complete.
Technology mix
54.7% F28D
share of records touching heat-exchange apparatus claims
Heat-exchange apparatus carries the heaviest claim load
F28D appears in 54.7% of the 3,334 records and F25B refrigeration and heat-pump claims in 41.9%, meaning more than half the field's activity touches core exchanger hardware rather than system-level air conditioning or niche electronics cooling.
Shares sum above 100% because records can carry multiple IPC codes.
Geographic filing
1,328 China
largest single receiving office in this dataset
Filing is heavily weighted toward China and Japan
China receives 1,328 of the tracked filings, well ahead of Japan's 585, the United States' 349, South Korea's 327 and the EPO's 311. Applicants building a defensive or offensive position in this technology should treat China and Japan as the primary jurisdictions to monitor.
Germany, tracked separately from the EPO route, shows 92 filings.
Eureka AI Agent
Looking for what nobody has claimed yet?
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to heat pipe two-phase flow patent landscape, with the prior art for and against each one.
Co-filing patterns
| Assignee | Co-assignee | Shared families |
|---|---|---|
| Sanyo Electric Co., Ltd. | Tokyo Sanyo Electric Co., Ltd. | 21 |
| Sanyo Electric Co., Ltd. | Sanyo Denki Co., Ltd. | 14 |
| Fujikura Ltd. | Ishikawajima-Harima Heavy Industries Co., Ltd. | 7 |
| Daikin Industries, Ltd. | Takenaka Corporation | 6 |
| Sanyo Electric Co., Ltd. | Sanyo Electric Air Conditioning Co., Ltd. | 5 |
| Sanyo Electric Co., Ltd. | SANYO COMML SERVICE | 5 |
| Gree Electric Appliances, Inc. of Zhuhai | Gree Electric Appliances (Wuhan) Co., Ltd. | 5 |
| Fujikura Ltd. | Tokyo Electric Power Company Holdings, Inc. | 4 |
Only 10 co-assignee pairs appear in this dataset, and the strongest link — between two Sanyo Electric entities at 21 shared records — points to internal group filing rather than cross-company joint development. Co-assignment is not a major feature of this field.
Source: Patsnap Eureka. Co-assignee relationships and derived observations. Derived from a Patsnap search on Heat Pipe Two-Phase Flow Patent Landscape covering 2015–2026, data cut-off 2026-08-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
What's Next
Turning this landscape into a filing decision
The dataset shows where claim density sits and where it thins out. The next step is testing a specific claim idea against that density before committing search or drafting time.
Stress-test a claim against the crowded core
F28D and F25B carry the heaviest claim density in this field. Before drafting around heat-exchange apparatus or refrigeration-cycle mechanics, check how closely a proposed claim sits to the most-cited prior art in that subclass.
Explore this in EurekaMap the long tail of single-filing entrants
With the top 10 ranked assignees holding only 21.2% of records, most activity comes from smaller or first-time filers. Tracking new entrants in narrower subclasses like H05K or F24D can surface competitive moves before they scale.
Explore this in EurekaWatch the 2025-2026 filing years fill in
Because publication lags filing by roughly 18 months, the apparent slowdown after 2020 is partly a reporting artefact. Revisit filing volume in this window again once 2025 data matures.
Explore this in EurekaSource: Patsnap Eureka. Forward-looking reading of the same dataset. Derived from a Patsnap search on Heat Pipe Two-Phase Flow Patent Landscape covering 2015–2026, data cut-off 2026-08-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
FAQ
Common questions about heat pipe two-phase flow patents
This dataset tracks 3,334 published records filed between 2015 and 2026 under air conditioning, refrigeration and heat-exchange IPC classifications. The true current total is somewhat higher because publication lags filing by roughly 18 months, so the most recent one to two years are still filling in. Treat 2024 as the last year with a reasonably complete count.
The dataset ranks 100 companies by filing volume, with the leader holding 162 records and the tenth-ranked assignee holding 33. Even so, the top 10 combined account for only 21.2% of all 3,334 records in scope, meaning the majority of filing activity comes from a long tail of smaller applicants rather than a handful of dominant players. This spread suggests the technology is still open to new entrants rather than locked up by a few incumbents.
Filing volume peaked at 195 records in 2020 and fell to 109 by 2024, a decline the dataset measures at -30% between 2021 and 2024. That is the most reliable growth figure available, because 2025 and 2026 filings are still being published and will rise as data catches up. It would be inaccurate to call the field in outright decline based on the most recent two years alone.
F28D, heat-exchange apparatus, appears in 54.7% of the 3,334 records and is the single largest technology bucket in this dataset. F25B, covering refrigeration and heat pumps, follows at 41.9%, with air conditioning and ventilation (F24F) and heat-exchanger details (F28F) forming a second tier around 17-18%. Narrower classes like domestic heating (F24D) and printed circuit cooling (H05K) sit under 5% each, marking more specialised or earlier-stage application areas.
China receives the largest share of filings in this dataset at 1,328 records, followed by Japan at 585, the United States at 349, South Korea at 327 and the EPO at 311, with Germany separately at 92. Applicants seeking broad protection typically prioritise China and Japan given filing volume there, while US and EPO filings matter for enforcement in those markets. The geographic spread also indicates where competitors are most likely to be building their own portfolios.
Answers are grounded in the same dataset. Derived from a Patsnap search on Heat Pipe Two-Phase Flow Patent Landscape covering 2015–2026, data cut-off 2026-08-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
Research Heat Pipe Two-Phase Flow Patent Landscape in depth with Eureka
Go past this page: query the whole heat pipe two-phase flow patent landscape corpus yourself, in your own scope.
Every answer comes back with patent numbers you can open.
Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
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.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company's registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.