Numerical simulation of deposition characteristics of microorganisms and particles mixed fouling in sewage heat exchange tube

Numerical simulation of deposition characteristics of microorganisms and particles mixed fouling in sewage heat exchange tube | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Numerical simulation of deposition characteristics of microorganisms and particles mixed fouling in sewage heat exchange tube Zhaoyi Zhuang, Jin Zhao, Caixia Zhang, Haiyang Yin This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4447058/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Sewage source heat pump technology is an innovative way of energy recovery. It can use the heat in all kinds of sewage to heat and cool buildings. This technology not only saves energy, but also has good economic benefits. At present, the main problem of this technology is the fouling problem. Microbial fouling and particle fouling are the main components of fouling in sewage heat exchangers. In this paper, the mixed dirt composed of microbial dirt and particulate dirt is taken as the research object. The deposition characteristics of mixed fouling in sewage were studied by numerical simulation. The mathematical model of mixed fouling deposition was established. The effects of various factors on mixed fouling deposition were simulated and analyzed by using the model. The results show that when the flow rate increases from u = 0.5m/s to u = 1.5m/s, the thermal resistance value of mixed dirt equilibrium in winter condition decreases from 27.97×10 − 4 m 2 ·K·W − 1 to 9.82×10 − 4 m 2 ·K·W − 1 , a decrease of 64.9%. At this time, the thermal resistance in summer condition is reduced from 36.41×10 − 4 m 2 ·K·W − 1 to 11.15×10 − 4 m 2 ·K·W − 1 , a decrease of 69.4%. The higher the inlet temperature, the higher the deposition rate of mixed dirt, and the shorter the time required for thermal resistance to reach equilibrium. However, the inlet temperature has little influence on the thermal resistance of mixed dirt. When the particle size of microbial particles increases from 0.1mm to 0.5mm, the thermal resistance value of mixed dirt when it reaches equilibrium in winter condition increases from 17.34×10 − 4 m 2 ·K·W − 1 to 21.55×10 − 4 m 2 ·K·W − 1 , increasing by 24.3%. At this time, the thermal resistance in summer condition increased from 18.94×10 − 4 m 2 ·K·W − 1 to 23.49×10 − 4 m 2 ·K·W − 1 , an increase of 24.0%. When the size of hard particles increases from 1µm to 40µm, the thermal resistance in winter conditions increases from 14.52×10 − 4 m 2 ·K·W − 1 to 19.56×10 − 4 m 2 ·K·W − 1 , an increase of 34.6%. At this time, the thermal resistance in summer condition increased from 16.68×10 − 4 m 2 ·K·W − 1 to 20.91×10 − 4 m 2 ·K·W − 1 , an increase of 25.4%. The thermal resistance of mixed dirt increased by 0.97×10 − 4 m 2 ·K·W − 1 in winter condition and 1.06×10 − 4 m 2 ·K·W − 1 in summer condition with an increase of 200 mg/L microbial particle concentration. The thermal resistance increases by 7.3×10 − 4 m 2 ·K·W − 1 in winter and 8.1×10 − 4 m 2 ·K·W − 1 in summer for every 200 mg/L increase in hard particle concentration. The research results of this paper can provide scientific basis for the design of sewage heat transfer system and have important engineering application value. Sewage source heat pump Mixing fouling Microbial fouling Particle fouling Fouling thermal resistance Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4447058","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":304829037,"identity":"ea9609d3-b29d-4be3-b514-dd0df45836e7","order_by":0,"name":"Zhaoyi Zhuang","email":"","orcid":"","institution":"Shandong Jianzhu University","correspondingAuthor":false,"prefix":"","firstName":"Zhaoyi","middleName":"","lastName":"Zhuang","suffix":""},{"id":304829038,"identity":"49c33a0e-db83-480f-873b-cf88b4c5baa6","order_by":1,"name":"Jin Zhao","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/klEQVRIie3RvUpDMRTA8YTAdTkaxxMo9BWOFPyAi32VgHC7ZBB8gcBdfYAr+hIuzqdcuHUQXQt1UArOt4uLHzTXTg5NOwrmDxkC50dIIkQq9RfDbpEAvVNOPr6+c9Dab0d65rKxCFnRMxVvQUI5TR0FUufkbVz0r8vXl+PzZ6BpYYN5AhIs24VbT+RNMyCkNzAPcw5mBkfKK3N1t54otIeIVMPepLDBzODEc6Z2IyTD0fsPEewOPNtHILZxAuhWp+zfu4H0zJsJorugjoRHLpT0Z2CqcRm9S78a3c7xsx6Gr2wCOR1qXY7bRYSsnuD3Xvr4fDfSbhxJpVKpf90SKIxPkaqPNOQAAAAASUVORK5CYII=","orcid":"","institution":"Shandong Jianzhu University","correspondingAuthor":true,"prefix":"","firstName":"Jin","middleName":"","lastName":"Zhao","suffix":""},{"id":304829039,"identity":"a28e2f4c-4fe0-49f4-ad00-b54d04018c4d","order_by":2,"name":"Caixia Zhang","email":"","orcid":"","institution":"Shandong Zhong Ke Neng Artificial Environment Co., LTD","correspondingAuthor":false,"prefix":"","firstName":"Caixia","middleName":"","lastName":"Zhang","suffix":""},{"id":304829040,"identity":"f05be5c9-b6c0-41a8-8953-6441b563a74c","order_by":3,"name":"Haiyang Yin","email":"","orcid":"","institution":"Shandong Jiuze Heat Exchange System Co. 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It can use the heat in all kinds of sewage to heat and cool buildings. This technology not only saves energy, but also has good economic benefits. At present, the main problem of this technology is the fouling problem. Microbial fouling and particle fouling are the main components of fouling in sewage heat exchangers. In this paper, the mixed dirt composed of microbial dirt and particulate dirt is taken as the research object. The deposition characteristics of mixed fouling in sewage were studied by numerical simulation. The mathematical model of mixed fouling deposition was established. The effects of various factors on mixed fouling deposition were simulated and analyzed by using the model. The results show that when the flow rate increases from \u003cem\u003eu\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.5m/s to \u003cem\u003eu\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.5m/s, the thermal resistance value of mixed dirt equilibrium in winter condition decreases from 27.97\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 9.82\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, a decrease of 64.9%. At this time, the thermal resistance in summer condition is reduced from 36.41\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 11.15\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, a decrease of 69.4%. The higher the inlet temperature, the higher the deposition rate of mixed dirt, and the shorter the time required for thermal resistance to reach equilibrium. However, the inlet temperature has little influence on the thermal resistance of mixed dirt. When the particle size of microbial particles increases from 0.1mm to 0.5mm, the thermal resistance value of mixed dirt when it reaches equilibrium in winter condition increases from 17.34\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 21.55\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, increasing by 24.3%. At this time, the thermal resistance in summer condition increased from 18.94\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 23.49\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, an increase of 24.0%. When the size of hard particles increases from 1\u0026micro;m to 40\u0026micro;m, the thermal resistance in winter conditions increases from 14.52\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 19.56\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, an increase of 34.6%. At this time, the thermal resistance in summer condition increased from 16.68\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 20.91\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, an increase of 25.4%. The thermal resistance of mixed dirt increased by 0.97\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in winter condition and 1.06\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in summer condition with an increase of 200 mg/L microbial particle concentration. The thermal resistance increases by 7.3\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in winter and 8.1\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e m\u003csup\u003e2\u003c/sup\u003e\u0026middot;K\u0026middot;W\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in summer for every 200 mg/L increase in hard particle concentration. The research results of this paper can provide scientific basis for the design of sewage heat transfer system and have important engineering application value.\u003c/p\u003e","manuscriptTitle":"Numerical simulation of deposition characteristics of microorganisms and particles mixed fouling in sewage heat exchange tube","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-05-31 03:27:35","doi":"10.21203/rs.3.rs-4447058/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"04d97367-67a6-4e42-a45a-351a50d49f1b","owner":[],"postedDate":"May 31st, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-07-01T11:51:33+00:00","versionOfRecord":[],"versionCreatedAt":"2024-05-31 03:27:35","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4447058","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4447058","identity":"rs-4447058","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}