Noritz Corporation

Kazuhiro Nishimura

Toshihiko Hamagami

Hisataka Hayase

Masahiro Iguchi

Kenichi Nakayama

Shigeo Sugie

Makoto Hirotsu

Kenta Yamanishi

Hideyuki Okada

Keisuke Iwai

Naoya Yoshida

A hot water supplier monitoring system includes a monitoring server monitoring hot water suppliers via a communication network. The hot water supplier supplies hot water by adjusting temperature of hot water heated by a heat exchange unit using combustion heat from combustion operation. The monitoring server accumulates operation data of combustion operation transmitted from the suppliers, and predicts and notifies malfunction occurrence for each supplier based on trend of change in the data over time. The data includes number of flame quenchings of the combustion unit in combustion operation. The monitoring server divides the suppliers into groups according to installation areas, compares the number of quenchings of same period among the groups, compares with previous number of quenchings of same group, and, for a specific group determined having an abnormal number of quenchings, excludes the data determined having an abnormal number of quenchings and predicts malfunction occurrence for each supplier.

Hot water supplier monitoring system

A hot water supply device includes a combustion part, a combustion fan, a heat exchange part, a water supply part, a hot water discharge part, and a control part. In the hot water supply device, in a pre-purge step of a heating operation, the presence or absence of a disturbance factor is determined based on rotational responsiveness and deviation of the combustion fan with respect to a scavenging rotation speed. When there is no disturbance factor, in an ignition step, detection of a failure sign is performed based on responsiveness and deviation of the combustion fan with respect to an ignition rotation speed.

Hot water supply device

A hot water supply device including an inlet pipe, an outlet pipe, a burner unit, a heat exchanger, an exhaust aperture, a first temperature sensor detecting a measured exhaust temperature of the exhaust gas, a second temperature sensor detecting a water temperature of water entering the inlet pipe, and a processor. The processor is configured to obtain an error between the measured exhaust temperature and an estimated exhaust temperature, and detects that scale clogging has occurred inside the heat exchange tubing based on an index which is generated using the error between the measured exhaust temperature and the estimated exhaust temperature. The estimated exhaust temperature is a first predetermined value that is determined using a numerical equation which has at least the water temperature of water entering the inlet pipe and a scale number of the hot water supply device as variables of the numerical equation.

A plate heat exchanger includes a plurality of plates stacked so that a liquid flow passage is formed on the inside thereof, and a gas flow passage through which heating gas passes, the gas flow passage being formed between the plurality of plates and including a gas inflow opening portion and a gas outflow opening portion positioned on an opposite side to the gas inflow opening portion, wherein the gas outflow opening portion has a smaller opening area than the gas inflow opening portion. Thus, when the heating gas passes through the gas flow passage, even if the volumetric flow thereof decreases due to a reduction in temperature or condensation, a reduction in the flow velocity of the heating gas can be suppressed. Hence, a reduction in a heat transfer coefficient can be suppressed, leading to an improvement in heat transfer efficiency, and as a result, reductions in overall size, weight, and manufacturing cost can be achieved appropriately.

Plate heat exchanger and water heater including same

A water heater has a primary heat exchanger having a first heat transfer tube, a secondary heat exchanger having a second heat transfer tube connected with the first heat transfer tube and being located higher than the first heat transfer tube, and an outflow path connected to an outflow-side end portion of the first heat transfer tube. The outflow path has an offset flow path portion including a rising portion which rises upward or obliquely upward from a connecting portion of the outflow path and the outflow-side end portion of the first heat transfer tube or from the vicinity of the connecting portion, the offset flow path portion being offset at a position higher than the outflow-side end portion. When hot water supply is temporally stopped, the water at high temperature in the first heat transfer tube flows into the offset flow path portion, thereby inhibiting such a disadvantage that water having a lower temperature than a target temperature is supplied because of a natural convection at the time of restarting hot water supply.

Growing community of inventors

Kobe, Japan

Kazuhiro Nishimura