Technology in WAMAK heat pumps
Innovations are standard in WAMAK heat pumps
Heat pump technology has been known for a long time. However, new challenges exist in today's requirements and the associated complexity of the development of heat pumps and application system with heat pumps. WAMAK is actively involved in various innovative projects which findings are transferred to the heat pump manufacturing process. This allows for agile use of new technologies based on knowledge, experience and close links with our partners.
Principle - basically very simple
The heat pump utilizes heat, which is below the human temperature and is therefore perceived as cold. Even at low temperatures, there is still enough heat to heat with a heat pump.
... how is it possible?
In the heat pump is a closed circuit, which is filled with the working fluid, refrigerant. This medium circulates continuously while the heat pump is running and changes its physical state. It evaporates, compresses, condenses and expands. The temperature of the working medium entering the evaporator is lower than the temperature of the source flowing through the evaporator, causing evaporation of the working medium. This vapor is compressed to a higher pressure and a higher temperature. This saturated vapor enters the condenser where it gives off useful heat. The liquid working medium already expands through the injection valve to steam temperature and pressure. The working fluid returns to the evaporator and the cycle is repeated.
EVI technology and its advantages in WAMAK heat pumps
With EVI (Enhanced Vapor Injection) several positive parameters can be achieved which are especially useful for heat pumps. By injecting the refrigerant directly into the SCROLL compressor head, the conditions in the refrigerant circuit of the system change. As a result, the heat pump outlet temperature reaches a flow temperature of up to 65 ° C even at low outside temperatures. Another advantage is the lower heat loss and the efficiency with decreasing source temperature.
At higher source temperatures, the EVI circuit can be disconnected allowing for heating and cooling capacity as well as input reduction by approx. 10% to 25%.
These features make WAMAK heat pumps with EVI technology an ideal choice for refurbishment or hot water heating systems where high flow temperatures are required.
Electronic refrigerant injection
The most important element of the heat pump in terms of efficiency is the heat source and the associated maximum use of this source. That's what the expansion valve does. It is said that the compressor is the heart of the heat pump. If we talk about an expansion valve in such an analogy, we would call it the brain. The expansion valve ensures that the evaporation of the coolant in the heat exchanger is controlled by valve opening and that no unnecessary overheating of the injected refrigerant occurs or that the refrigerant in the liquid state comes to the compressor. If the refrigerant in the evaporator overheats, the system efficiency is lost and unnecessary overheating of the compressor occurs.
The expansion valve in the heat pump can be thermostatic with statically adjustable superheating or electronic. The signal from the electronic temperature sensor is used to open and close the discharge opening. This allows the superheat to be set more accurately and controlled over a wider range of condensation and evaporation pressures.
The electronic refrigerant injection system consists of at least four components. Exact electronic expansion valve, controller or controller for EEV (superheat controller), pressure transmitter with transmitter in the control unit and temperature sensor.
APS - Energy recovery system and coolant subcooling
A unique solution for the design of the cooling system has made it possible to achieve significant efficiency in the operation of our air-to-water heat pumps. By additional subcooling of the refrigerant upstream of the injector, we have created a solution to improve the two main factors in operating the heat pump. These are the heating power and the efficiency. In addition, the stability of the system has increased in both the heating and cooling phases of heat pump operation.
The most critical process when operating air-to-water heat pumps is defrosting the outdoor unit, which draws energy from the ambient air. As the air contains moisture, it collects between the fins of the heat exchanger, freezes at lower temperatures, builds up and gradually reduces the efficiency of the system.
Through years of experience and intensive focus on the development of air-to-water heat pumps, we have developed a system that allows a highly efficient defrost process and prolongs times between defrosts. The APS system consists of a combination of heat exchange of residual heat and the use of low temperatures when removing energy from the outside air.
In addition, the fins of the heat exchanger are specially treated with a thin film for quick "gliding" of ice, which also helps the unique shape of the outdoor unit. This saves the energy needed for melting, since sometimes the frost does not have to be changed from solid to liquid.
Energy saving fans with EC motors and bionic blades
For air-to-water heat pumps, WAMAK uses state-of-the-art high-tech EC motors with speed control. These are axial fans, which have been specially developed for use with heat pumps, with the energy parameters of the fan being very good. No less important, however, is the quiet operation even under unfavorable weather conditions.
Economic circulators of class A.
Circulation pumps of class A reduce the total heat pump system consumption considerably and thus increase the efficiency. All circulation pumps are modulated by a PWM signal and ensure a uniform heating water flow through the heat pump.
SHR Heat pumps for heat recovery and with flow temperature up to 82oC.
SHR - Super Heat Recovery is a new class of heat pumps, with new types of compressors that redefine the work area of the primary side. They allow a direct use of the source even with high temperatures up to 45oC and allow at very high COP a flow temperature up to 82oC. We have presented 3 series. WW SHR with a compressor. TWW SHR with two compressors in tandem Installation in a refrigeration circuit and the WW HeavyDuty modules which allow variable design of the heat pump machine.
Asymmetric plate heat exchangers made of stainless steel
WAMAK heat pumps up to 30 kW have built-in asymmetric heat exchangers, which leads to an increase in the heat transfer surface, a better approach of the condensation and evaporation temperature of the refrigerant on the primary side, water or brine. In addition, this design of heat exchangers helps to reduce the pressure loss on the source side (water or brine), which is up to 50% lower than with conventional heat exchangers. In addition, this design reduces the total amount of refrigerant in the heat pump.
98% Reduction of vibration of the compressor unit
For the first time, we have achieved a 100% separation of compressor unit from the base frame unit. This was done with the help of Sylomer pads which are glued in between the main baseboard and the heat pump board with compressor and heat exchangers. This design has helped to reduce the vibrations transferred onto the side panels of up to 98%.