Alternative Energy Utilization with Industrial Heat Pumps

Sustainable Heat Generation for District and Process Heating

Industrial facilities and district energy networks worldwide face increasing pressure to replace fossil-based heat generation with sustainable alternatives. Modern industrial heat pumps enable efficient use of wasted heat from processes, seawater, river water, or process water as renewable energy sources. Combined with electricity from renewable generation, they deliver large amounts of CO₂-neutral process heat for industrial and municipal applications.

HTT Heat Transfer Technology AG offers proven solutions for energy recovery and sustainable heating with its BUCO Falling Film Evaporator systems. Acting as evaporators within large-scale heat pump installations, these falling film heat exchangers rank among the most efficient components for utilizing alternative and environmental energy sources.

Learn more about HTT’s solutions for district heating systems!

BUCO Falling Film Evaporators in High-Temperature Heat Pump Systems

BUCO Falling Film Evaporators by HTT are successfully deployed worldwide as evaporators in high-temperature industrial heat pumps. They are based on pillow plate or thermo-plate heat exchanger technology, which provides exceptionally high heat transfer coefficients (U-values).

In operation, process or environmental water – for example from rivers, lakes, or seawater – is evenly distributed across open film surfaces. The heat exchanger transfers the thermal energy to the refrigerant (e.g., NH₃ (ammonia), CO₂ (carbon dioxide), or R1234ze) under optimized evaporating conditions. This results in robust, energy-efficient systems ideal for waste heat recovery and district energy supply.

Key Advantages of BUCO Falling Film Evaporators

The BUCO Falling Film design provides outstanding thermodynamic and operational advantages for industrial heat pump systems:

• Very high heat transfer coefficient due to structured plate geometry
• Adjustable evaporation temperatures minimizing energy[S1]  losses
• Up to several megawatts of heat transfer capacity per exchanger
• Reliable operation even with water temperatures near freezing
• No frost damage due to open-surface design
• Easy cleaning during operation and low maintenance requirements
• Stable efficiency under varying flow rates and temperature levels
• Low control effort with high COP (Coefficient of Performance)
• Long service life due to corrosion-resistant stainless-steel design (V4A), suitable even for seawater

Explore our industrial heat exchanger technologies!

Energy Flow and System Integration in Industrial Heat Pumps

Within the heat pump cycle, the falling film evaporator absorbs the environmental heat flow (Q₋u) from surrounding sources. This enables efficient heat recovery from natural or industrial water systems.

Typical Application Scenarios:

• Utilization of seawater, river water, or lake water as heat sources
• Waste heat recovery from process cooling or condensation stages
• Integration into district energy or district heating networks
• Contribution to carbon-neutral industrial energy systems

This technology forms a key component in modern sustainable infrastructure, allowing industries and utilities to decarbonize heat supply chains.

Application Example: Heat Pumps in District Energy Systems

A real-world example illustrates the performance potential:
In a coastal residential district, cold seawater at approximately 5 °C is used as the heat source. The BUCO Falling Film Evaporators extract energy from this water, providing low-temperature heat (around 12–15 °C) to a primary network.

This thermal energy is then upgraded by decentralized heat pumps within each building to produce domestic hot water (45 °C) and service water (60 °C). The result: a completely CO₂-neutral, secure, and cost-efficient heating system.

Read about successful district energy projects implemented with HTT technology.

Energy Efficiency and Environmental Benefits

Industrial heat pumps utilize environmental heat and electrical energy to generate heat far more efficiently than combustion-based systems. Compared with fossil-fired boilers, they reduce primary energy demand by up to 70%, achieving overall system efficiencies (COP) of 3 or higher.

Modern monitoring and control systems ensure stable operation, rapid detection of anomalies, and optimized performance over the system’s lifetime – guaranteeing reliability and maximum energy efficiency.

HTT Heat Transfer Technology AG – Expertise and Innovation in Industrial Heating Solutions

HTT Heat Transfer Technology AG combines decades of engineering experience in industrial refrigeration and process heating with continuous innovation. In the field of falling film evaporators for industrial heat pumps, HTT ranks among the leading providers in Europe and beyond.

A showcase project in Kiel, Germany, demonstrates the potential of large-scale CO₂-neutral district energy using seawater as the heat source – powered by BUCO Falling Film technology.

HTT develops custom-engineered evaporator systems for energy providers, utilities, and industrial clients of all scales – supporting the transition toward sustainable and resilient heat infrastructures.

Contact our experts for project consulting and feasibility studies!

Technical Overview of Industrial Heat Pump Systems

Technical Parameter	Description
Heat Exchanger Type	Falling film heat exchanger (pillow plate, open-surface design)
Application	Evaporator in centralized heat pump systems
Heat Sources	Seawater, river water, industrial waste heat
Refrigerants	NH₃ (ammonia), CO₂ (carbon dioxide), R1234ze or others
Capacity Range	Multi-megawatt thermal performance
Materials	Stainless steel (V4A) up to titanium, seawater-resistant
Operation Mode	Flooded, pumped or dry expansion evaporation
Unique Features	No icing, easy cleaning, low control effort
Target Industries	District heating, chemical, food, and energy sectors

Frequently Asked Questions (FAQ)

What are industrial heat pumps used for?

Industrial heat pumps are designed to recover and upgrade heat from renewable or waste sources such as seawater, process water, or exhaust air. They supply efficient, CO₂-neutral heat for industrial processes and district heating systems, significantly reducing fossil energy consumption and emissions.

What is a BUCO Falling Film Evaporator?

A BUCO Falling Film Evaporator by HTT is a high-efficiency, open-surface heat exchanger that transfers thermal energy from environmental or process water to a refrigerant. It enables stable and sustainable operation in high-temperature industrial heat pump systems and supports efficient waste heat recovery.

Which refrigerants are suitable for BUCO Falling Film Evaporators?

HTT Falling Film Evaporators operate efficiently with natural refrigerants such as ammonia (NH₃) and carbon dioxide (CO₂), as well as modern low-GWP refrigerants like R1234ze, depending on the specific system design and temperature range.

How do falling film heat exchangers improve energy efficiency?

By maintaining a continuous thin liquid film on the heat transfer surface, falling film heat exchangers achieve superior heat transfer performance with minimal energy losses. This results in higher system efficiency, lower operating costs, and enhanced long-term reliability.

Can falling film evaporators be used in seawater or near-freezing conditions?

Yes. Thanks to their open-surface design and corrosion-resistant stainless steel construction (V4A), BUCO Falling Film Evaporators can operate safely with seawater and at water temperatures close to freezing, without the risk of icing or damage.